Nole will not play in the U.S. Open!
Let's be clear on that. The U.S. will not change its regulations, Nole will not get vaxed -- it's as simple as that.
Nole can still end the year on a strong note. He will play in Laver Cup (if that's really a thing - I think it isn't). He will play for Serbia in Davis Cup. He will play in Paris and the year-end championships and he can still finish with some positive momentum.
I have no idea what will happen with Australia next year, but this is all on Nole.
Nole is the best player in the world, but at the end of the day it's his fault he can't play tennis in some countries. All he has to do is get vaxed, he refuses -- he loses.