The Hollywood Reporter has an extensive Dan Harmon profile out today called "The Rise and Fall (and Rise) of Dan Harmon," with a ton of new info about the reasons the Community creator was fired and rehired onto his show. Here's a section finally explaining why NBC and Sony let him go last year:
Harmon was forced out — a move the studio had considered making earlier — for a collection of reasons, including erratic behavior and an oddball leadership style, according to multiple sources with knowledge of the situation. Many say he regularly showed up hours late to work and on one occasion outright disappeared to San Francisco for a few days surrounding the SF Sketchfest comedy festival. A tug of war between his perfectionist tendencies and his procrastinator nature led to table reads being delayed — and, at least twice, canceled — and periodic all-nighters. (Former staffers tell tales of songs on season three's musical episode being written the weekend before shooting, and the set of the same season's video game episode still being built the morning production was supposed to start.) There was his liquor intake, which was substantial enough for Harmon to label himself a "ninja of alcoholism," and his habit of falling asleep during the workday, which his staff documented on a Tumblr account called Sleepy Harmon. Some of the show's writers insisted they'd depart if Harmon remained for season four.
Other highlights from the profile include a description of how Community star Joel McHale went to bat for Dan Harmon and got him hired this year, a quote about Harmon from Chevy Chase ("Dan and I are friends again. He's brilliant and can be very funny. The reason I wanted to do the show in the first place was Dan's writing. And I stand by that. But I have to go now, I'm very busy writing Community's Ice Capades Extravaganza."), and Dan Harmon himself talking ambitiously about the new season ("I want to astound people with a season five that makes an unbeatable argument for a sixth season. I want the headlines to say, 'Holy crap, Dan Harmon pulled it off.'").