(contains spoilers for Avengers Infinity War and )
So, I've been thinking about this year's Marvel movies - Avengers: Endgame, and Spider-Man: Far From Home..
Something I've noticed is that Kevin Feige specifically said that the two new movies would shake up the Marvel Cinematic Universe for years to come.. not just Endgame.
None of the people they've shown in the Spider-Man trailers were people we know survived the snap, and in fact there were several we knew did not inc Nick Fury and Spider-Man himself.
What if Spider-Man is set in a parallel universe where life continued on as normal after Infinity War? They don't know this calamity happened, but Fury's fury-sense is tingling and he wants Spider-Man to help him work out what's going on. Where if at the end they all come back to the original universe only to discover that they were missing for [amount of time] and there's a huge outcry against the Avengers for letting it happen, leading to the original Avengers leaving for good, maybe with Captain Marvel.
I guess we'll find out in a few weeks when Endgame comes out.