While James Cameron definitely has his hands full with three Avatar sequels in the works, once he is finished with those movies, he'll be a free agent again. Therefore, he could, theoretically, be available to direct any future installments of Alita. After all, Cameron has previously directed Aliens and Piranha II: The Spawning (even though he disowns this one). So, it's not out of the realm of possibility that he would direct a sequel to a movie he didn't helm the first time around. And considering how hands-on he was with the first Alita movie, and how much it bares his influence, he's clearly very passionate about this property. Also, since it'll take a while for these proposed sequels to come into fruition, he'll likely have the luxury of time at his disposable when it comes to signing off on this potential directing gig. Chalk it up to a maybe?