Terry loves interest from other distribution companies
Final Update: NBC has acquired Brooklyn Nine-Nine just 1 day after FOX cancelled it. NBC (via Universal) produce the show already, so their costs would be less than other networks, making it a more viable prospect. 13 episodes will air next year, probably January in after the mid-season break.
Brooklyn Nine-Nine, much loved but criminally under watched, has been cancelled by FOX after 5 seasons. If you follow the Renewed / Cancelled Predictions page (and you should, it's pretty accurate) this won't have come as a major surprise. While its critical reception has always been fantastic, both for its humour and ability to touch on social issues without being heavy handed, it has been in the "Likely to be Cancelled" column for the last couple of seasons.
It seems that even though FOX don't own the show (it's produced by Universal, ie NBC) it was waiting for, or was paid handsomely for, the 100th episode: the usual syndication deal break point.
Other, more conspiratorial theories are spreading across the internet. FOX has also cancelled The Last Man On Earth (after 4 seasons) and The Mick (after 2 seasons), and Ghosted literally has been ghosted by the network; it has been completely wiped off the schedule since a single episode in January, with no word about any further episodes. New Girl was also cancelled, though it got a final, but much shorter season that ends next week.
All these comedy show cancellations come on the heels of rumours of a possible revival of Last Man Standing, Tim Allen's show that aired previously on ABC. Allen has been vocal about the reasons he believes the show ended; politics, and his role as a Conservative man's man.
After the recent success of Roseanne (ironically on ABC) and the shifting political climate, FOX may be hoping to tap into the conservative-leaning portion of the audience that feels that TV (and Hollywood) has been ignoring their concerns in favour of more overt political correctness in shows like Modern Family and Fresh Off the Boat. If this is true, Allen may be expecting a hefty pay day, leaving little budget for already under performing shows. Time will tell if such conspiracies are given weight, or just that FOX wanted to shake up their roster.
Update (10:11pm UTC): FOX has indeed picked up Last Man Standing for the 2018-19 season.
It's not all bad news for the Nine-Nine though. Both Netflix and Hulu reportedly approached Universal within hours of the cancellation, with an eye to picking up future seasons. Both companies have history in this arena; Hulu picked up The Mindy Project (also cancelled by FOX) while Netflix already work with Universal on Unbreakable Kimmy Schmidt (which is due to end after this next season) and they have worldwide distribution rights on B99. Universal is apparently still absolutely interested in producing further episodes, so hopefully one of these companies can make a compelling enough pitch.
Brooklyn Nine-Nine might not yet be in TV jail.
Update 2 (00:22pm UTC): Netflix and Hulu have reportedly passed on picking up the show. TBS and NBC might still be in talks.