@selfagency point of clarification — most discussion of post indexing has to do with in app fulltext search, which is a service currently only some misskey instances offer. So in the context of the discussion, no its not really already happening
That checkbox refers to whether search engines like google / bing / etc will index your profile. If you’re concerned about privacy it may be worth checking anyway! but the risk profile of generalized search engines is basically a completely different conversation
@selfagency they haven’t actually released the service they proposed yet and at another point threatened to release it to everyone with zero safeguards
regardless, i maintain that the distinction between being indexed by generalized search engines and in-app fulltext search are is an important one when it comes to discussions of search
@Satsuma the person who has created the new controversial full-text search has stipulated that it will respect this user setting whereas it does its crawling externally