User blog comment:MisterWoodhouse/The first migrations to the Unified Community Platform/@comment-32042378-20201203000618/@comment-1038387-20201203110558

Fandom also uses MediaWiki. They're a major stakeholder, second behind Wikipedia. In fact, it's the whole point of this upgrade, to get closer to the core software.

Miraheze uses current MediaWiki. Despite allowing some more customization, it does not have any of the features from Legacy that are gone, like Chat, Threaded forums, WikiActivity or Walls.

Miraheze has also very poor branding and recognizability, and its only reason to seems to be for "people who don't like Fandom". You may fork your wiki (not move), but there's no guarantee your community or readership will follow.