Mastodon is preparing changes to allow searches of public posts, and a decision has been made to make the condition for allowing it a "discoverble" for accounts.
https://github.com/mastodon/mastodon/pull/26344
I have an opinion on this but discussion is not allowed.
If users want to keep their searches restricted as before, the server administrator should recommend that users turn off the "discoverble" setting.
Doing so will result in more users disappearing from directory and account searches.
@noellabo are you aware of the "Unlisted" post privacy setting - "visible for all, but opted-out of discovery features"? Would posting as "Unlisted" when you don't want the post to be searchable resolve your concern?
