As is plainly obvious to anybody following 20th Century Fox's X-Men movies, they are in a total state of flux right now. That has left a number of open questions, many of which are tied to its biggest stars. The contracts for Michael Fassbender, Jennifer Lawrence, James McAvoy, and Nicholas Hoult are supposedly up, and not everybody seems keen on returning. Fassbender doesn't seem to be for it or against it, in his conversation with Empire while promoting Assassin's Creed. He's just as confused about the X-Men and Magneto's fate as the rest of us...
"I don’t know to be honest. I haven’t made any sort of decision on it because I have no idea what’s happening next with the franchise to be honest."
Fassbender has been a centerpiece ever since donning the Master of Magnetism's helmet with X-Men: First Class, so if he has no idea what's going on then that's a bad sign. We've heard rumblings that New Mutants, which may be titled X-Men: New Mutants, could take over as the main teamup series, possibly with McAvoy back as Charles Xavier. At this point, who knows? Kinda looks like Deadpool is the main franchise at this point, doesn't it?