> Auto-addition of a Wikipedia tag when adding Wikidata was also recently removed from iD

There is no such PR for this at https://github.com/openstreetmap/iD/pulls

In any case - the real reason why adding a wikidata= field doesn't automatically add the wikipedia= one is that you're suppose to select the local language Wikipedia.

Kind of wish these hadn't been removed as it's simpler easier to directly click on the Wikipedia link rather than having to click twice to get to a POI's article.