Since nvidia drivers do not properly implement implicit sync, this protocol not existing is the root cause of flickering with nvidia graphics on Wayland. This MR being merged means that Wayland might finally be usable with nvidia graphics with the next driver release.
EDIT: Nvidia dev posted that support is planned in the 555 driver, with beta release planned for May 15: https://github.com/NVIDIA/egl-wayland/pull/104#issuecomment-2010292221
I’m all for progress, I hope it helps people, but I haven’t had any issues with my Nvidia card and my two monitors on Wayland.
If I remember right, the syncing issue was particularly egregious when you run windowed X11 programs on Wayland. So it could be that you got lucky.