Board Thread:Support Requests - Getting Started/@comment-45171933-20200309021537/@comment-9605025-20200309023458

Once the Unified Community Platform (UCP) is ready for rollout, this is something new wikis will need to be concerned about (see here). However, MisterWoodhouse clarified in the comments section that these requirements for new wikis will not be retroactively applied to existing wikis.

So your wiki should be safe. That being said, it probably would have been better if you had simply edited the existing wiki and then applied to adopt it.