Can I reassign a paid seat if a user I was backing up leaves?
Yes! The domain admin can use the License Manager to remove the paid seat and reassign it to another domain user.
*If you want to retain the backed up data for the user that’s leaving, a paid seat must be assigned to that user account. You can also use Spanning Backup to export that data out of the account or perform a cross-user restore before deleting the user from the domain.