“Hard as it is to think about leaving the company I love, and the people I love in it, it is the right time for me to do so,” Plepler said in an memo to staff. “So many of you, and many others before us, have made HBO a cultural and business phenomenon.” He referred obliquely to an “inflection point” for the company, and said that Stankey had been “nothing but gracious” as they negotiated his exit. But there has been undeniable tension among employees since AT&T rolled out its vision for the future of Time Warner, which has been renamed WarnerMedia and includes Turner (with brands such as TNT, TBS, and CNN), the movie studio Warner Bros., and HBO.

“It’s going to be a lot of work to alter and change direction a little bit,” Stankey told HBO employees last July, in remarks that were published by The New York Times. “I want more hours of engagement … It’s not hours a week, and it’s not hours a month. We need hours a day.” HBO’s business model has always been focused on the channel’s reputation for high-quality, prestige material. Original shows tend to air only on Sunday nights, with most of the rest of the network’s TV programming dominated by movies and documentaries. Where Netflix might roll out multiple original shows a week, HBO debuts them only every few months.

Rumors had circulated that WarnerMedia was talking to Bob Greenblatt, a former chairman at NBC and Showtime, about a high-level position that would oversee both HBO and Turner, making him Plepler’s boss. That extra layer of oversight, combined with Stankey’s plans to increase the quantity of shows, might have been too much for Plepler to consider. His track record as chief executive includes the debut of Game of Thrones, an awards-laden smash hit that buoyed the future of the company and helped boost profits to $2 billion in 2017. He also launched HBO Now, a streaming-only subscription service that helped keep the company’s brand steady as online apps became a more dominant form of TV viewing.

For Stankey, and presumably for AT&T, it was not enough. Netflix’s fire hose of original content, combined with the entry of the massive tech companies Amazon and Apple into the television game, has the rest of media spooked. Disney is preparing to roll out Disney+, a premium streaming service that will launch on the backs of its Marvel and Star Wars brands. WarnerMedia is prepping its own bundled streaming service, which HBO might be a part of (WarnerMedia also controls the sizable TCM and MGM film libraries, which were part of the now-defunct FilmStruck, another casualty of consolidation).

The departure of Plepler means he can exit on a high note, with HBO still airing well-regarded TV, boasting a healthy subscriber base, and putting up solid profits. But it’s still a sign that things are probably about to change for good. Seeing an executive get emotional farewell tweets from celebrities is rare, but Plepler has gotten an outpouring of support from associates such as Jeffrey Wright (who said there were “not many like [him]”), Alex Gibney (who hailed him as a “powerful impresario and creative force”), and David Simon (who called him a “genuinely wise shepherd”). In saying goodbye to a collaborator, they’re also bidding farewell to a more bespoke approach to art that is likely on its way out at the company, and in the world of television at large.

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