User blog comment:MisterWoodhouse/The first migrations to the Unified Community Platform/@comment-27159607-20201214123555/@comment-24258073-20201216231353

No, lol. We can't make exceptions willy nilly.

Opting out would mean that you wouldn't be able to receive future updates, because updates are no longer being made to the Legacy platform which will be removed shortly, so the wikis that opted out would end up getting removed.

I personally would much rather migrate to UCP because it has various updated features, even if it means losing some of the Fandom specific features.