An Azure Windows file server was backing up its files using the MARS agent into the recovery services vault and is listed as a protected server (see below). This server has been superseded but before I delete it, I want to check that the MARS backup will be preserved. My client needs to keep this historical backup for many years.
Deleting the VM has no effect on the backup itself. Also have a look here
Even if you would delete the backup with all the recovery points the backup data would be retained for 14 additional days (assuming soft delete is enabled)