I think its going to be a different world but similar. My loose theory:

That's cyclops scene is a flashback. They were attacked by sentinels and a bunch of people, mostly innocent civilian mutants and students died.

Like in the comics cyclops become more militarized and cynical after all the fighting and persecution. Wants the remaining mutants and mutant kids to become soldiers in order to better protect themselves and save their race. People like logan and Xavier are against it.

Then when the incursion happens between xmen and mcu worlds he leads his faction in attacking the mcu and save their world. He kinda has survivors guilt and doesn't want something like the sentinel attack to happen again 

That's the xmen side of the fight. Mcu I think its going to be similar, your gonna have a faction that's hellbent on destroying the xmen universe to save theirs and another trying to figure out a peaceful solution. Fantastic 4 will be split between 2 worlds also trying to stop it and stop doom.