User blog comment:MisterWoodhouse/Creating new wikis on the Unified Community Platform/@comment-24361909-20200303203008/@comment-1807002-20200303221023

Yes, I did a merge article history with same articles (it's an ordeal lots of deleting, renaming and restoring) but some stand alone pages that were undesirable could be delete once merged so it is at least in deletion history if the desire to pull up again but if it is not imported and deleted when the other wiki is deleted it is pretty much lost. Basically, they want a full import if you are going to merge and delete other wiki.