Heh, actually X11 forwarding over SSH obsoleted Xauth knowledge long ago. If that doesn't work anymore it's yet another thing to be pissed about.
Truly, we already run XFCE in our LTSP academic computer labs and kiosks as the Ubuntu Gnome default was not easy to manage in that sort of environment. I can only imagine the pain and unhappiness in trying to manage an environment running a mix of X, Unity/Wayland, SPICE, and VNC apps all at once. It's pretty easy to imagine big win for Xubuntu and similar. Inevitably the Linux distribution admins find easier to manage is what will be installed, used, and advocated for.