Here's my big question: what happens to Guardians of the Galaxy 3 now that the Thanos storyline is over?
Drax's defining motivation is that he wanted to kill Thanos. Well, now Thanos is dead, and not by Drax's hands. Does that make him happy, or frustrated, or what?
Likewise, they have reset the Quill/Gamora relationship back to square one, undoing everything that happened in GOTG 1 and 2. I think that one can work to their advantage, as they can just have the two fall in love all over again, and falling in love is an easier story to tell than having a mature relationship.
Likewise, Nebula is in an awkward place.
They have the GOTG3 script already, I assume it was written to be post-Endgame?