Will restoring Windows 10 from restore image destroy Linux ext4 partitions?
You used Windows Backup, a deprecated product which is the quirkiest of its kind. It's impossible to predict what will happen when restoring, but we have had several posts about problems created after doing that. The message was correct, in the sense that the restore destroyed partitions that it had no business touching at all.
The lesson for the future is not to use Windows Backup. Microsoft has renounced it and is no longer developing this software dating from Windows 7.
For safe backups, my favorite is AOMEI Backupper Freeware, but there are other alternatives.