If a published URL such as that in your first example – which may be indexed by search engines, bookmarked, printed on paper, linked to by third parties or otherwise still in circulation – contains false information or implication, then it should be redirected (status 301 “moved permanently”) to the corrected article or to a stand-alone correction, at a more suitable URL.

Returning a 404 “not found” error code might be seen as indicating an administrative error, or as a routine time-based deletion, rather than a correction.