In the Wikimedia projects, Special:Import should have an additional box that could be checked to automatically:
- add the destination page as a sitelink to the Wikidata item that corresponds to the source page if this item already existed, or
- create a Wikidata item and add sitelinks to both pages to it if the source page wasn't linked to any Wikidata item.
This feature shouldn't be available for user/talk/MediaWiki pages.