That was a horrible explanation(Proffesor X erasing memories)
. Lets keep it real,if they can't simply explain X-Men and mutants existing due to butterfly effect. They need to just give X-Men there own thing completely seperate from the Avengers. I'm starting to think that needs to happen anyway to be honest. Drop the Avengers and put all of your focus into X-Men. We can start the timeline right around Civil War era where there was a crackdown in super powered beings. All the Avengers are still alive and will just be featured characters from time to time in the X-Mens story,from the X-Mens perspective . You could start making Avengers movies again from that point. But they should cut the breaks on all Avengers related properties outside maybe GOTG since they are in space ,and Black Panther who is his own entity in Wakanda. They need to just say its a fresh start,the stones and time travel caused a butterfly effect and its a new beggining. Seems like the easiest way,especially since nobody is buying the whole "Jumping through time doesn't create a butterfly effect
" that you guys have been trying to sell us since the movie dropped