TBH after 1st teaser trailer, I used to think that if there's any film that can go over Avatar is TLK. Simply because it has sort of no weak zone unlike Avengers or any other superhero film having weak Europe and Japan, which Endgame overcome to an extent.
Now after trailer and Endgame, I think it might not be that easy and of course, I am no longer assured of it being as good as original after 1st trailer. That said, if it's as good as TJB, $2B will be cake walk but now, I don't see it going over 2.25 Bn as well