From [this MSO post](https://meta.stackexchange.com/q/71712/184716):

> The Precognitive badge appears in the badge list on every site to announce the presence of Area 51, and its primary function.
>
> Since Area 51 is itself about creating new sites that don't exist yet, the thought process is supposed to be:
>
> > hmm, I can't get [the precognitive badge] on this site, but I could get it on some hypothetical future site I might be interested in.
>
> Yes! Thus, based on seeing this badge and reading about it, a user is incentivized to:
>
> 1. visit Area 51 (and we provide a handy link in the badge description itself) -- win
> 2. look at upcoming site proposals -- win
> 3. follow likely proposals, which requires reading them and deciding if they have a chance -- win.

So in conclusion it seems that Stack Exchange knows these badges (or at least Precognitive) aren't possible on this site, but still thinks their presence on the Badges page is a net positive. I'm not sure I agree, but in any case this isn't likely to get changed.