We have a small number of orphaned objects (location = -2) which have matching content hashes in the files table. The query I use to determine this is:

SELECT *
FROM mdl_files
WHERE contenthash IN (
  SELECT contenthash
  FROM mdl_tool_objectfs_objects
  WHERE location = -2);

Am I correct in my understanding that while the orphan_objects task marks files that have been deleted as orphaned (sets location = -2) there is no corresponding task which resets them to location = 2 if a file with a matching hash is later uploaded?

I'm not sure why this happens but one possibility: a file is deleted in Moodle, the orphan_objects task sets the associated object tuple to orphaned, but before the delete_orphaned_object_metadata task runs to remove the tuple (and potentially file depending on the deleteexternal setting) an identical file is uploaded.

Is there any harm in resetting tool_objectfs_objects.location to 2 if a file exists in the files table?