X11 has been, and still is, a vital piece of technology at the core of professional Unix-like workstations since decades. It has a proven track record of supporting enterprise-grade applications with long-term protocol stability and platform compatibility. It has matured over decades. XLibre is an actively developed fork of the X.Org X11 server, initiated by the most active X.Org developer and supported by the open source community.
An incompatible alternative, Wayland, is being aggressively pushed by IBM = Red Hat = Gnome = Fedora = freedesktop.org. However, it is not ready to succeed X11 as it its governance model leads to never-ending discussions and prevents even the most essential functionality from existing. Think twice before abandoning Xorg. Wayland breaks everything!
It is time that the open source community reclaims what was ours to begin with. This page lists distributions supporting XLibre so that you can make an informed choice.
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That's what I've heard too, but you never know. People change their minds all the time for all sorts of reasons. Hopefully they will support X11 for as long as possible. By the way, are you aware of any GUI IceWM configurator that allows you to change settings you normally need to edit config files for?