In 8.3 we added a special kiosk session for specialized single-application customer deployments.
Unfortunately, at the time I inadvertently shipped the xsession file from that kiosk session in both the right place (gnome-session-kiosk-session) and duplicated in the wrong place (gnome-session-xsession).
This is because the xsession subpackage uses a glob:
so it go both session files.
So by default in 8.3 and 8.4 we show a "Kiosk" session in the login screen gear menu that doesn't work (since it's missing the rest of the files from the kiosk-session subpackage).
We should mop that up, and drop the kiosk xsession file from gnome-session-xsession