There’re discussions to drop the X11 backend with the release of GTK 5.
A question of what will happen to the X11 backend is not the same as an active push for the removal of X11 just for the sake of it, as it was claimed.
Chances are at least the Valve side of Wine development work will not care for Wine’s X11 support either after SteamOS will only run Proton natively on Wayland instead of XWaxland as is the case now.