The `FILE_CHANGED` value is only used by the GIO file monitoring code AFAICT. That is never enabled because it has issues with multiple triggering (possibly due to the documented erorrs and incompletnes of inotify(7)) but its left there in case "somebody" figures it out and fixes it. If not at some point it will have decayed too far and should be removed. IIRC it needed the extra flag value because it used the infobar so the status had to persist.