During FCV upgrade, the config server can start using authoritative database metadata before a shard transitions its local FCV. Consider the following scenario:

1. The config server enters upgrading FCV while a shard remains at the old FCV.
2. createDatabase runs through the config server. Because FCV there is kUpgrading, the CreateDatabaseCoordinator will choose to use AuthoritativeMetadataAccessLevelEnum::kWritesAllowed and therefore will persist the database metadata both globally and in the shard catalog.
3. Later, a dropDatabase runs on the shard. There, the FCV is still at FCV8.0 state, therefore dropDatabase will use AuthoritativeMetadataAccessLevelEnum::kNone and will not delete its shard catalog metadata.
4. The dropDatabase completes after having removed the global database entry but not  the durable shard-catalog entry. This leaves stale database metadata on the former primary shard.