Apparently I didn't word that section very well, because many people took away this impression. My apologies.

Factorio will continue to support X11 for as long as SDL does, in other words, essentially forever. The only change here is that X11 is no longer required for the game to launch at all. SDL will load whichever video driver is available at runtime, or if you have both, you can choose which one to use in the graphics settings.

I don't see anything to indicate that they're dropping X11 support? It sounds like they're dropping dependencies that would require X11 to be installed.

It's time to make WaylandX, for running Wayland applications on X. Well, I happily use Wayland so I won't use it, but maybe you would.

I don't think they are planning to do this; they are at least maintaining support for whatever MacOS (Metal?) and the Nintendo Switch use in addition to Wayland, which suggests to me they are dropping X11 as a hard dependency not as a usable backend.

Just run the last version that supports X11?

You could use Proton to play the Windows version in x11 just fine, I'm pretty sure.

Same here.