Im not sure,but I feel like they are going to reset everything with X-Men. These last MCU movies we are seeing will be the last ones connected to this universe. You may still have t.v shows connected to it but no more movies.
Then they will build an entire universe around xmen like they did with Avengers. And just like that another 30 year run

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So you will have a new Cap,new Iron Man,new Thor,new Hulk etc in the Xmen universe. If they are going to build up to an Xmen vs Avengers. How would they do that with this current C list Avengers lineup

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Feels like the smartest way to do it. And no need for elaborate explanation of where they were when Thanos came. People are just about fatigued of this universe anyway. So i dont think youd see a major uproar. Set up your tv shows with these final films,then reboot it all. Might even get that Tom cruise as Iron Man afterall