Board Thread:Support Requests - Getting Technical/@comment-31398281-20200604083733/@comment-9605025-20200605010031

A legacy wiki is any wiki that is not using UCP. Per this blog, you can volunteer for early migration but "upgrading" the wiki is not something you can actually do on your own. That said, Fandom has already started migrating some wikis (see here). If you are unfamiliar with UCP, you can check things out on the UCP test wiki.