User blog comment:MisterWoodhouse/Blogs are now available on the Unified Community Platform/@comment-36727063-20200820130322/@comment-26339491-20200820172531

That's because the new comments and message walls run on an entirely different technology, just like Discussions. They don't use MediaWikia, and therefore aren't hooked into Recent Changes. We're aware that users do need some way to monitor social activity on their wiki, and are looking into how to solve that problem.