If you try to move a page to a name that already exists, there is an error page [[https://en.wikipedia.org/wiki/MediaWiki:Articleexists|:en:MediaWiki:Articleexists]], but '''it does not contain a link to a target page'''. I believe it would be useful to add a parameter $target with the target name, so that the link can be added.
The reason why we need such a link is that sometimes there is a problem: if I would like, for example, to move [[:en:Russian Empire]] to [[:en:Russian empire]], then I can not just enter a target name [[:en:Russian empire]] into search field as it will be automatically corrected to a name of the existing page [[:en:Russian Empire]], thus I should do more actions to open this page.
The idea of such a link was approved on Russian Wikipedia's technical forum, see [[:ru:ВП:ФТ#Переименование в существующее название]].