Removal of Xwayland abstract namespace socket breaks snap applications

We've received a number of bug reports from people trying to use X11 based snap confined applications on GNOME 3.38's Wayland session:

• https://forum.snapcraft.io/t/apps-wont-run-and-crash-on-gnome-wayland/20322
• https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1897224
• https://bugzilla.redhat.com/show_bug.cgi?id=1883621

From the look of it, this is due to !1424 (merged), dropping the abstract namespace X11 socket. This causes problems as the Snap sandbox gives each application a private /tmp that the snap is free to use as it sees fit. This means that the host system /tmp/.X11-unix directory is not visible, which wasn't a problem as the X client libraries would connect to the matching abstract namespace socket.

Is there any chance of reverting this change?

I see that this change was intended to fix #1289 (closed), where Mutter was only auto-starting Xwayland on connection to the abstract namespace socket. It looks like it would be possible to keep Flatpak applications working if Mutter polled both the regular and abstract namespace sockets as a trigger to start Xwayland.