In T324535, extension RealMe was deployed to production. Normally the communities need to follow the https://meta.wikimedia.org/wiki/Requesting_wiki_configuration_changes process to get an extension enabled. If one doesn't usually the task will be stalled until there was such consensus. In this case though it seems that the process was not followed for some reason and the extension was deployed.
The extension seems to serve a very narrow subset of users who use the Mastodon social media. For example by my estimation probably only up to 10 users on Ukrainian Wikipedia are likely to be Mastodon users, out of over 3000 active users the Ukrainian Wikipedia has. I am not sure the extension would find its support if there was a proposal to enable it (perhaps it would, I don't have a crystal ball, but I don't believe there was a chance to have a say).
Thus at least retrospectively I believe it would be a good idea to see if there is a community support for the change which has now cluttered the preferences (see also T341331). If there is no consensus *to keep it enabled* on some wikis, then it should be undeployed from those wikis. If there was however such consensus obtained somewhere already, it should be mentioned somewhere. The closest thing to it I find is T322717, but it has no on wiki consensus mentioned.