Well, when I wrote this stuff for the first time a couple of years ago, NVIDIA's official position was "we have no plans to support Wayland". Even now I suspect X will be around for years.

I will be the first to cheer X's demise, as we've had so many problems with multithreading and X, but we have no choice right now.

Here's an overview from last year showing nvidia's wayland support under way:

https://www.phoronix.com/scan.php?page=news_item&px=mtgxmde

X11 won't be going away any time soon.

Also, the EGL backend should work just fine in Wayland.