A set of merge requests were opened that would effectively drop X.Org (X11) session support for the GNOME desktop and once that code is removed making it a Wayland-only desktop environment.
Going along with Fedora 40 looking to disable the GNOME X11 session support (and also making KDE Plasma 6 Wayland-only for Fedora), upstream GNOME is evaluating the prospect of disabling and then removing their X11 session support.
Some concerns were raised already how this could impact downstream desktops like Budgie and Pantheon that haven't yet fully transitioned over to Wayland. In any event we'll see where the discussions lead but it's sure looking like 2024 will be the year that GNOME goes Wayland-only.
They still haven't solved the problem of a Gnome Shell crash taking down my entire session with it. I need to be able to restart the shell independently of the Wayland compositor for me to switch.
pretty sure the KDE work will be at least partially compatible with other desktops. one of the demos shown was specifically using the feature to swap between Wayland desktops without losing app state
ubuntu already compile gnome with the fix(edit: i confused it with triple-buffering, that ubuntu compile gnome with, idk if ubuntu compile gnome with the fix to don't take down the entire session), but the merge request is there, and it work, idk with gnome didn't merged it still, maybe other priorities?