The seminar was to be on media leadership. Dozens of students filling a classroom at Yale University in April were there to learn about the business from a man who had commanded attention in TV control rooms and corporate boardrooms for decades before a stunning exit last year.

What they got was remarkable candor about that exit.

Jeff Zucker, who had been president of CNN for nine years, told the group that he believed the network’s former owners used his relationship with Allison Gollust — who was also in attendance — as a pretext for removing him, three people familiar with his comments said.

In front of the students — where other high-profile media executives, including Bob Iger of Disney, were scheduled to speak the same day — Mr. Zucker compared his failure to disclose his relationship with Ms. Gollust, CNN’s former communications chief, to handing over a dangerous weapon.

“I gave them a gun, and they shot me with it,” Mr. Zucker said, according to the people.

That Mr. Zucker would compare his forced departure to a gunshot wound underscores the depth of his frustration with his last days at a network he controlled with exacting detail for years.

The complaint wasn’t unusual for Mr. Zucker, 58. He often compares notes on the media business with former colleagues and industry acquaintances, many of whom call him to grouse about the current state of CNN.

But his gripes have become more frequent of late, and he has made no secret of his unhappiness with the terms of his exit from CNN or his low regard for the performance of its current leader, Chris Licht. In a sense, he is now serving as a kind of grievance switchboard for current and former employees of the news network, many people who have spoken with him said.

Mr. Zucker’s criticism may be painful for executives running CNN to hear second- and thirdhand. But also painful are the numbers: The news division, which once regularly made more than $1 billion in profit annually, generated just $750 million in profit last year. And its ratings were down more than 30 percent in the first quarter of this year compared with the same point in the 2020 presidential election cycle, when Donald J. Trump — a major driver of cable news viewership — was still in the White House, according to Nielsen data.

As it has geared up to cover the 2024 campaign, the network has committed some unforced errors. Last month, CNN hosted a town hall with Mr. Trump in New Hampshire that was criticized for airing false information. Mr. Licht’s leadership and problems at the helm of the network were dissected at length in a 15,000-word Atlantic article that was published Friday.

Many anchors Mr. Zucker hired or promoted, including Jake Tapper, and Kaitlan Collins, who moderated the town hall, are still in prominent spots in CNN’s lineup. But he has found himself banished from the control room during a major news cycle, including an indictment of former President Trump and the opening acts of the 2024 presidential election.

He has not been hiding away, though. He and Ms. Gollust traveled to Las Vegas to see a Taylor Swift concert, and last month he attended the Sports Emmy Awards at the invitation of Bryant Gumbel, along with the former “Today” anchor Matt Lauer. His new office in Manhattan — where a life-size statue of the Incredible Hulk looms in the entryway — is just blocks from CNN’s former New York headquarters in Columbus Circle.

And he is trying to get his next act off the ground, starting a new venture called RedBird IMI with $1 billion to spend on acquisitions in the digital media, sports, entertainment and news industries.

This article on Mr. Zucker is based on interviews with more than four dozen of his associates in the media industry who spoke on condition of anonymity to avoid jeopardizing their relationship with him. He declined to comment, but through a spokeswoman described his attitude toward CNN.

“It is wholly unsurprising that Jeff Zucker, the architect of CNN’s unprecedented success, would have deep misgivings about the direction the network has taken since he left,” said Risa Heller, a spokeswoman for Mr. Zucker. She added that it was also no surprise “that he gets asked a lot, publicly and privately, and regularly from former colleagues, about what he thinks of CNN now.”

Months after he left CNN in February 2022, Mr. Zucker met with his successor, Mr. Licht. The organizers of that meeting — industry confederates who know both men — hoped that a lunch at Mr. Zucker’s house on Amagansett’s tony Hedges Lane would clear the air.

Mr. Zucker had been privately critical of Mr. Licht’s leadership of CNN, according to people who have spoken with him, and the two men hadn’t met since Mr. Zucker was pushed out.

The get-together didn’t kindle much bonhomie between the media executives, who had been friendly in the clubby world of TV news. Mr. Licht was seeking a rapprochement. Mr. Zucker was asked to give advice. But afterward, the former CNN president griped that Mr. Licht didn’t take any of his pointers, said a person familiar with his feelings following the meal.

“This is all very sad for Jeff,” said Kenneth Lerer, the co-founder of HuffPost and former chairman of BuzzFeed. “He should move on with his life. It’s disheartening to see.”

Mr. Lerer has a distinct perspective on the situation: He is a close friend of David Zaslav, the chief executive of CNN owner Warner Bros. Discovery, and was once also friendly with Mr. Zucker.

Mr. Zucker’s criticism has rankled executives of Warner Bros. Discovery, which owns CNN, according to people familiar with their thinking. They suspect Mr. Zucker has leaked unflattering information about the network’s operations to the press.

He has also been candid about what he sees as the missteps of CNN’s former parent company, AT&T, and its leaders, including the former WarnerMedia chief executive Jason Kilar, many industry acquaintances who have spoken with Mr. Zucker in recent months say.

Executives at Warner Bros. Discovery believe Mr. Zucker is waging a proxy war against Mr. Licht, undermining his leadership from afar, according to three people familiar with their thinking.

Mr. Zucker’s criticisms have come at a particularly inopportune time for Warner Bros. Discovery, which was created last year from the fusion of WarnerMedia, CNN’s parent company at the time, and Discovery, the home of “Dr. Pimple Popper” and “90 Day Fiancé” and is still trying to get CNN onto solid footing.

A spokesman for Warner Bros. Discovery said in a statement that the company was confident in the direction of the network and in Mr. Licht’s leadership of it. “We set a high bar for ourselves and while we know that it will take time to complete the important work that’s underway, we have great confidence in the progress that Chris and the team are making and share their conviction in the strategy,” the statement said.

Underlying the grievances are tensions between Mr. Zucker and Mr. Zaslav, who picked Mr. Licht to succeed Mr. Zucker at the top of CNN. Once great friends and business allies — and a regular pair at the East Hampton Golf Club — the two men have grown apart since Mr. Zucker’s ouster, people familiar with their relationship say.

In March, Mr. Zaslav visited CNN’s Manhattan headquarters and criticized Mr. Zucker’s leadership of the network in a meeting with Mr. Licht’s lieutenants, according to someone at Warner Bros. Discovery. In the meeting, Mr. Zaslav told CNN executives that Mr. Zucker’s gripes — which had made their way to him — were ironic, given that Mr. Zucker had once remarked that Mr. Licht was the one executive who could do the job if he ever left the network.

Since he took over CNN’s parent company, Mr. Zaslav has fired back, telling employees in a private meeting that there was a “period of time” when it became an “advocacy network,” a not-so-subtle dig at segments that were stridently critical of President Trump, who drove massive ratings. Mr. Zucker disagrees with that characterization, people who have spoken with him say, believing that on his watch the network’s policy of calling out Mr. Trump’s falsehoods led to journalistic and financial success.

In another gathering this spring, Mr. Zucker said that his departure from CNN was the hardest period in his life, adding that the episode made his bond with Ms. Gollust stronger, according to a person familiar with his remarks. He also said that the punishment he received didn’t fit the crime.

When Mr. Zucker was forced out of CNN last year, he and the network’s parent company negotiated over a statement designating his failure to disclose his relationship with Ms. Gollust as the reason for his exit. “I was required to disclose it when it began but I didn’t. I was wrong,” Mr. Zucker wrote in a memo to employees at the time.

According to two people familiar with Mr. Zucker’s departure from CNN, a company investigation into his conduct by the law firm Cravath, Swaine and Moore found multiple violations of CNN’s standards and practices, including taking part in advising former New York Gov. Andrew M. Cuomo.

Ms. Heller, Mr. Zucker’s spokeswoman, said Mr. Zucker did not advise Mr. Cuomo.

“As we have said numerous times, Mr. Zucker never advised Andrew Cuomo, directly or indirectly,” she said. “He was asked to resign for one reason only, failure to disclose his relationship.”

For Mr. Zucker, who has been in senior management ranks since his 20s, when he became executive producer of “Today,” his abrupt exit from CNN represented a marked change of pace. He soon began to explore his options, gravitating to the familiar territories of sports and media. Years ago, Mr. Zucker told a writer for the Harvard Crimson, the campus newspaper he worked on as an undergraduate, that he hadn’t taken a day off since finishing college.

Shortly after his ouster from CNN, Mr. Zucker began plotting his next move, meeting with advisers, former colleagues and industry stalwarts at upscale watering holes like the Core Club in New York and the Four Seasons in Los Angeles. But even as he planned for the future, Mr. Zucker was thinking about his past.

In the summer, he traveled to Jackson Hole, in Wyoming, for an off-the-record gathering of media executives. In a fireside chat at the event, he was asked for his view on the current direction of CNN and in his answer criticized Mr. Kilar for the way the executive handled his exit, according to two people familiar with his remarks.

In his new endeavor, the investment vehicle Redbird IMI, he has told confidants he is interested in building a company that owns digital publications targeted at specific audiences, similar to Condé Nast, publisher of Vogue and The New Yorker. He has held talks with owners of digital-media start-ups, but those conversations haven’t yet resulted in a deal. He is now one of at least three suitors exploring a deal to take a majority stake in Air Mail, the media company founded by the former Vanity Fair editor Graydon Carter.

In recent months, he has also met with Jeff Bezos, the Amazon founder and owner of The Washington Post, according to three people familiar with their conversation.

One company Mr. Zucker is not in talks to acquire is CNN, according to people familiar with his plans. Though he has told some associates he would be interested in acquiring the network should it come up for sale one day, he has lamented to others that CNN’s current owners, Warner Bros. Discovery, have damaged the network so much through cost-cutting that he wouldn’t be interested in owning it.

But Mr. Zucker has explored a deal for the network before. In late 2020, he and Andrew Morse, CNN’s former digital chief, met with Emerson Collective, the umbrella company founded by Laurene Powell Jobs, and had preliminary conversations about a potential spinout of the network. Without informing Mr. Kilar, his boss at the time, Mr. Zucker referred Emerson Collective’s interest to an executive at AT&T. The deal never happened, and AT&T ultimately turned to Discovery.

There are signs that Mr. Zucker believes he could once again be calling the shots at a media organization. He has told associates that he’s open to an operational role at one of the companies he buys, and many of his confidantes believe he could still land another big corporate job.

A professional revival for Mr. Zucker has some precedent. After he was fired as chief executive of NBCUniversal in 2010, Mr. Zucker created a new daytime show for Disney with the former “Today” host Katie Couric that he called a “tremendous opportunity.”

Then he got the CNN job. “Katie” was off the air two years later.