backups should be made as often as possible (daily or more often) and no "hook" will save you. Especially the site could break after core update, theme update or plugin update, sometimes after changing some settings.
nothing should be tested on production, so if you're not sure your site breaks, and you worry about it, use DEV server.
Backup automatisch erstellen, bevor das WP Autoupdate, seit 3.7 im Core, los läuft, um so den letzten Stand im Backup zu haben.