Yes, comic book writers also tend to play it fast and loose, but they stick closer to the same page more often than movie screenwriters, who just make a total mess of things.
At least the comic book writers have what could be called a "bible" of the main storyline to work from, both in DC and Marvel. It does annoy me when they retcon certain things, but comics have had better consistency than Hollywood.
Well, the X-Men going back to Marvel and being integrated into the MCU won't happen for years, so we won't know what's gonna happen until then.
Deadpool 2, Dark Phoenix, and New Mutants come out this year, with Gambit, X-Force, and who knows what else in development; and the MCU still has Ant-Man & The Wasp, Infinity War, Black Panther, Captain Marvel, Avengers 4, and two more Spider-Man films to clear out of its system. Then they have to figure out what they're gonna do after contracts expire and actors leave roles and X-Men and Fantastic Four have to somehow be worked in with the Avengers in the MCU, and how the MCU is going to be refitted to accommodate them. I don't think we'll know anything until at least 2020.