User blog comment:MisterWoodhouse/Profile and Message Wall on the Unified Community Platform/@comment-36153576-20200309204758/@comment-43707041-20200309205120

Then use talk pages. They only did this so that it would be overall better for everyone. It can't support wiki text because it won't be part of MediaWiki. It makes it much easier for them to stay up-to-date with the MediaWiki installation.