The US Open always is a bit noisier off court during matches - people running up and down the stairs to get drinks etc and lounging about chatting in the upper tiers, but this latest turn is about cash. Grand slams are supposed to be special.
I watched some of it yesterday and I can see what they're going for, basically a sort of T20 for tennis filled with the best players/biggest names. It must be incredibly annoying for doubles specialists though who have just lost a slam tournament...