The idea with their patches, which is in collab with Valve, seems primarily focused on Wine and so Proton for Steam Play due to the differences in how Windows handles things to Linux that Wine needs to support for getting good performance. As the original patch explained:
The use case lies in the Wine implementation of the Windows NT interface WaitMultipleObjects. This Windows API function allows a thread to sleep waiting on the first of a set of event sources (mutexes, timers, signal, console input, etc) to signal. Considering this is a primitive synchronization operation for Windows applications, being able to quickly signal events on the producer side, and quickly go to sleep on the consumer side is essential for good performance of those running over Wine.
They went onto explain that current Linux Kernel interfaces fell short on performance. With their code being used, they saw a reduction in the CPU utilization in multiple titles running with the Steam Play Proton compatibility layer when compared with current methods. Additionally it doesn't rely on file descriptors so it will also solve issues with running out of resources there too.
The new patch in discussion goes about it a different way to before. Instead of extending the current interface in the Linux Kernel, they're going with building a new system call 'futex2'. It's early on as they're still building it up with this adding the new interface, that they can then expand upon.
In short: it would make Linux gaming better with Wine / Proton in future Linux Kernel versions. However, it would likely have other uses too. You can see the patch set here which is currently under discussion.