I agree the case will be rare, but that might happen in such way, possibly:
- The cluster was deployed by third-party group;
- Admin key is distributed across multiple clients (administration, automation, orchestration, metering collection or something like that) by customer;
- Customer used cluster for long years;
- Eventually the cluster was completely lost;
- Initial installers are unavailable;
- Customer forgot about cluster key importance;
- Someone new deployed the fresh cluster;
- Customer restored his data from backup and tries to go into production;
- Customer sees all his Ceph-oriented tools are inoperable;

What the installer should do?
1. Reinstall the cluster from scratch with restore data from backup again?
2. Investigate the debris of customer's tools to find the way for key change?

Where are guys from HOLLYWOOD?! This is the blockbuster scenario!