I doubt it changes much. The US did not really accomplish much at that conference anyway.
I mean what more could happen? The USSR gets ALL of Europe? The agreements did not exactly favor the US and anything that the USSR didn’t like they would latter ignore, Sofrankly I don’t see where a lot of useful anything came out of said confidence.
The war was going to finish the way it did one way or the other. The west was going to take what it did and the YSSR was going to take what it did and not much was going to change, Conference or no Conference.