I think this email discussion is the part that would make it official
I think we have been a bit slow, GeoNetwork 4.4 is presently acting as stable with 4.2 in maintenance mode. It is just that GeoNetwork 5 is under development so there is no “latest” folks are in position to run.
I have not head much on this thread, and during the CVE disclosure updated the release history to indicate 4.4 is stable, 4.2 is maintenance (and nearing end-of-life):