Out of all these potential stories that could be movies, this one is the least likely to happen. The premise is simple enough (if you can handle insane comic book stories): Six X-Men from six different realities are assembled onto a team that learns the multiverse is breaking, and they have to fix it. These X-Men learn that the fabric of the multiverse is dying and the realities they came from are now broken and should any of them die in their quest to fix it, they will be transported back to their broken reality. Simple enough, right?
This is a tough sell to a general audience, especially if they only get one anchor in the film with a character they know. The best way to handle this, I think, is to bring back actors to play their characters from past movies, just not exactly the same characters. For example, Alan Cumming as Nightcrawler would be a great addition to the team but maybe he could play the “Age of Apocalypse” version of Nightcrawler. What the comic book does really well is playing on the familiar. Characters appear who are dead in one universe, the servant of bad guys in another, or not born at all in another. A time-jumping action piece full of over the top characters is not something a studio would ever risk, but it would be a dream come true.