The funny thing about Hollywood is that, there are no coincidences. Never. So just a few days ago Joseph Kosinski started chatting up a sequel to Tron: Legacy, and while he said the movie, which would have been titled Tron: Ascension, wasn't dead it was unlikely to happen. Well, apparently Disney liked some of the buzz Kosinski's comments got because suddenly there's a new Tron movie on the way. The catch is that it's a reboot and Kosinski's got nothing to do with it.
THR reports Jared Leto (!?!) is in very early talks to be part of a Tron reboot in both a producing and starring capacity. Here's the thing: he'd be playing Ares, a character created for Tron: Ascension in a story that uses elements from that canceled film. Kosinski must be like "Come on, Disney! What up wit dat?" No writers or director is attached at this point.
Now this is super early so maybe Kosinski does get back involved, IF the film happens at all. Remember, Disney canceled the sequel in 2015 for a reason, and it's that Tron: Legacy cost a lot of money for very little return.