Man...All of Phase 3 was about the Infinity Stones, and all of Phase 4 seems to be Multiverse shenanigans....I'm not sure how good it'll all work. The Stones left room to make whatever story you wanted to tell, and that half the McGuffins turned out to be Infinity Stones was just some extra lore and some stingers. But every story now has to tie up to extra-dimensional crossovers and so on. I don't mind the concept, I'm just a bit weary that I - and other viewers - will get burned out and confused about Thor-549613 and Hulk-331874 coming along to save Earth-31239741 from Zuul-951475.
And it'll be a god-awful mess trying to keep multiverse rules at least somewhat consistent over several movies and different directors and writers.
I mean, that teaser had me looking forward to it, but...we're still in the lead up to Dr Strange in the Multiverse of Madness, how much of this movie, and Loki, and WandaVision, etc will people need to know and remember; or how much of the big movies will have to be given over to recapping stuff people need to know? It's...well, it may work, but it may turn away people not used to so much interconnectedness and comics-style cross-over.