User blog comment:MisterWoodhouse/The first migrations to the Unified Community Platform/@comment-35253867-20200625230214/@comment-24258073-20200626110922

Making it optional is out of the question. But allowing us to keep an uneditable archive of the wikis we care about before the migration is something I would strongly support.

Because it would help us to ensure that we add the necessary CSS that we'd written prior to UCP and add it to UCP in such a way that it fits. Because a lot of non-UCP related CSS won't work very well on UCP wikis. And therefore keeping uneditable archives to look back on would be very beneficial.