This is an exciting time for comic book fans as Disney has purchased Fox, making the characters licensed to Fox available to the Marvel Cinematic Universe. This mostly concerns the characters related to the X-Men (it may also include the Fantastic Four, but that is more complicated).
There are numerous ways that this could be done. They could have the existing MCU being in one universe and the Fox characters in a parallel earth, but able to crossover (such as the Flash and Supergirl on CW).
They could also just have the existing X-Men movies as having occurred in the MCU, with the characters just haven’t met. This may be awkward since both have used different Quicksilvers.
There have been some good X-Men movies, especially the first couple with James McAvoy as Professor X. I also quite enjoyed Logan. But the truth is that the X-Men movies have some of the worst continuity of any comic book movie series. It is just a mess.
I would like see them total reboot the X-Men movies as part of the MCU. I would especially like an original team of Professor X, Beast, Cyclops, Iceman and Marvel Girl. Start it completely over and slowly add new characters over the course of new movies.
I would also like to see some X-Men movies without Wolverine. I like Wolverine (especially since he is Canadian), but the X-Men can be interesting without him.
I don’t know what they will do. Fox already has the popular Deadpool movies (a character I can’t stand). They are not going to reboot him and he is connected somewhat with the X-Men. I would be happy if they kept Deadpool in his own universe and his own versions of the X-Men.
It will be interesting to see how it all unfolds.