User blog comment:MisterWoodhouse/The Unified Community Platform Editor and our first release date/@comment-37336800-20200309175852/@comment-24006128-20200309180004

There is not a specific date planned, but we will be allowing wikis to decide whether they want to migrate early to help us test the platform more thoroughly.

>Alternatively, would it be possible for the FANDOM staff to create a testing wiki (fandom staff specifically so there aren't duplicates) so we can test things out and make sure they work prior to the mass rollout?

Last line of the blog ;)