To give more detail: Proton uses a hacky workaround called fsync. Fsync was developed by the Wine developers but was explicitly not merged into Wine because, by their own admission, this is a really hacky workaround and it’s definitely not the right way of doing things.
For games, using fsync is far better than not using anything, and so Proton uses fsync. Apparently there’s recently been concern that the fsync workaround is going to become a bottleneck in modern games (not entirely sure the reasoning why), and so the Wine developers pushed for the development of NTsync, which is basically fsync if it weren’t a hacky workaround. NTsync alleviates the bottleneck that fsync creates, making it more robust, less hacky, and more futureproof.
In short, don’t expect any noticeable performance increases, but Proton might work more consistently and it might improve performance for future games
But will this make the eggs cheaper??