No. His form is just not there yet and it won't be back in time to win the USO. It's quite likely it will never come back enough for him to contend in a slam again, but I'm not willing yet to completely give up on that slim possibility.
As much as I love to see that happen as a Fed fan.. chances are very slim.. I say Tsitsipas may have more chances than Federer, and I believe any youngsters chances are also very slim. I think it is between Rafa and Novak. The story is going to be, can Rafa climb that Mountain Nole? We know he has always been the fighter ... but can the iron man take it to Thanos . I do hope for some 2012 like battle.. just for the sake of making it interesting story.
Federer will participate, but I am guessing might not get past Round 4... He got lucky in Wimby to be in QF.. I don't think on hard courts that happens as his natural instinctive game can't hide all current weaknesses same as grass.
Extremely slim chances. But he made the QF at Wimbledon with very few matches on his back, so he might have a slight chance with a good draw and a few upsets (He'd have to avoid Djokovic, Nadal, Tsitsipas and Medvedev mostly).