Not sure if you'd consider it a bug, but IMO it is because when I click on it (and whilst not logged in) I get a Page Not Found... Why show me a duplicate if it's not found (which arguably means it's not a dupe)!
That's deliberate. Links that are added in to point to canonical questions do not automatically get removed if they themselves are deleted.
If it was not closed as a duplicate it would have been closed as a product/app recommendation.
Either way it has been deleted.