Fedora and debian default templates now use xfce instead of gnome in qubes 4.2

As you know in 4.2 fedora and debian templates now use xfce instead of gnome. Templates with gnome are currently in the repository, but are they planned to be supported in the future? What is the exact reason for switching from gnome to xfce?

See here. In short, yes, Gnome templates will continue to be supported and the reasons for switching to xfce are lower resource usage of the xfce-flavor templates as well as problems with Gnome-flavor-specific apps.