"I met with Kevin Feige a couple of months ago and we had long, long conversations. And there have been moves and suggestions, which include Charles Xavier. Here's the problem... If we had not made Logan, then yes. I would probably be ready to get into that wheelchair one more time and be Charles Xavier. But Logan changed all that."
So, it certainly sounds like Marvel Studios have been considering folding the likes of Patrick Stewart's version of Professor X and the rest of 20th Century Fox's X-Men into the Marvel Cinematic Universe in some capacity. Whether this would have been for ongoing projects,