(split out from T60698: Enable fulltext search in edit summaries (and logs) )
Special:WhatLinksHere only displays links to the target that exist on Wikipedia pages. Editors would find it valuable to also know where links are present in edit summaries or log entries. This would be valuable for making decisions on what to do with certain redirect pages - users may not want to delete a redirect if it was linked in an edit summary somewhere, and would therefore break that link, for example. Another use case is in deciding where a particular redirect should be pointed - understanding current usage is important, but links in edit summaries cannot be easily reviewed.