I'm not sure if this would be considered a bug or not.
If you highlight a group of tracks and update using an action or the tag panel, you can still save the original values back over what was just updated.
- highlight all tracks in an album
- execute an action (or use View, Tags) to remove the album name
- with the tracks still highlighted (default), make a change using the tag panel to any field and save (or just save with no change)
- the album name has been saved back to the tracks