If you don't have a dedicated sysadmin who's always on top of new Gitlab versions, then the alternative to automatic upgrades is letting insecure versions run for an arbitrary time until someone takes the time to upgrade. Gitlab is merely 1 of the 200 things we have to keep track of.

Besides, we already make weekly automatic backups, stored remotely and encrypted. And Gitlab automatically makes a locally-stored backup before each upgrade, which is good enough unless the disk fails right after we discover that the upgrade is broken.