Does the AutoCleaner process not handle abandoned dupe links? Or do now-dead dupe links just need to be hidden from non 10k users?
Side note: Should there be a 'Question you are trying to remove/delete is marked as the original of [this] duplicate question' warning when removing/deleting questions?
Edit #1 - As Kobobby has pointed out, it appears that the auto-cleanup is only for the 'Linked' section in the side bar. So does this mean there is NO automated checking for abandonded duplicate question links in questions? If so, that might need looking into.