Probably not, but dammit I hope so. I'd love to see it dump on James Cameron. I'm certainly no expert when it comes to this kind of stuff, but from what I understand Avatar did as well as it did because of a perfect storm of good luck and circumstance when it was released.
Having said that, if any movie can take the crown off Avatar then it'll be Endgame. And unlike Avatar, Marvel deserves it. So much work has gone into this franchise, unlike Avatar which just leeched off a shiny new novelty tech for its appeal.