Thief and the Cobbler release year

The Thief and the Cobbler from Richard Williams (https://www.imdb.com/title/tt0112389/) now has a release year of 1992. This is wrong, because the movie was first released in 1993. 1992 has become the default release year because of an added workprint version from 1992 in the release date section. However, that release date is wrong because this was a private showing to studio executives, who then fired Williams off his own movie. It was not a public screening in any way. That workprint had it's first public showing in 2013 (details about the first public showing are noted here, plus notes about how it was the first public showing: https://www.oscars.org/calendar/thief-and-cobbler) I've tried to delete it from IMDB or change the release date but it will not accept it, despite the sources I provide.