It's been a while since I did enterprise backup, but when I did, most backup software had a 'bootstrap procedure' that you could use even if you were completely destroyed.

First, most enterprise software does not need a license for restorations, only for backups. In a disaster recovery scenario you're unlikely to have the keys.

At end of every backup run/day, an e-mail is sent out with the tapes and offsets that have the indexes and configuration backups. You can send this message to an e-mail address that is separate from corporate e-mail (in case that gets wiped as well); back in the day you could send it to /dev/lp0 (and stick a copy in the box that the offsite tapes are transported in).

So even if your entire infrastructure is wipe (e.g., see NotPetya and Maersk), there's still a starting point for restoring your restore-backup server, and rebuilding up your infrastructure.

Remember: your backups have to be inaccessible to attackers.