If the drive is removed or completely formatted then odrive will not sync any changes to the cloud. It actually won't be able to because the root folder(s) will no longer exist, which means odrive has no frame of references to make any changes.
There are several things that need to take place for files to be deleted in the cloud by odrive. Even if a file or folder is detected as being deleted, it will be held in the "odrive trash" and not committed to the cloud until the user empties the trash. https://docs.odrive.com/docs/sync-changes#section--empty-trash-