Azure/CloudBackups

Backup of VM created from Market place image can't be restored once marketplace image has been removed.

For our discussion here is somethings I would like to understand.

The risk to TWG?
- Am I correct that for a marketplace deprecated image, Azure can’t restore the backup if there is a failure?
Understand why Azure can’t just restore a disk/VM that has been backed up daily?
- What is the mechanism preventing the restoration?
- How is the VM backup still dependent on the marketplace image?
Does this impact Windows and Linux Servers or only 3rd party Marketplace images?
Workarounds fix’s?
- Redeploy new images and move all config etc. (Very disruptive)
- Restore single disk and attach to 2nd VM? Some data recovery?
- Create our own custom image and migrate to it.