There are the Guidelines:
Wikipedia: If possible, link to Wikidata instead, which serves as a bridge for all languages. If no Wikidata item exists, only link to the languages which are relevant to the artist. This usually means the artist’s native language(s). The English Wikipedia is always allowed.
And a blog post from 2015:
So basically Wikipedia links are depreciated (there is almost always a Wikidata item if there is a Wikipedia article and if there isn’t you can create it with a few clicks even without logging in), but there is no “This relationship type is deprecated and should not be used.”-warning and Wikipedia links are not included in any report about depreciated relationships.
A little bonus obsticle is that a search for wiki edits claims it includes removals “created after 2013-07-08” but actually doesn’t include any relationship removals.
When adding a Wikipedia link there should be a warning that it is depreciated and a link to a short article explaining how to find the correct Wikidata link or create one if it doesn’t exist.
And there should be the following reports or bot actions if an entity has:
- a Wikipedia and a Wikidata link
- and they match or the WD item links back to the MB entity -> a bot could remove the WP link
- they don’t match -> put the WP link on a report so a human can fix it.
- a WP but no WD link:
- and the WP link is connected to a WD item that links back to the MB entity -> a bout could replace the link
- otherwise -> report
- a WD link that doesn’t link back to the MB entity -> report
- a shared WD link with other entities -> report unless:
- the WD item is for a song and it’s linked to a single and a work on MB
- the WD item is linked to artist entities that are linked with “performs as” relationships.