Specifically here you're right, but the hypothetical that came to my mind when reading GP was in similarity with email.

I want to reach my friend Pete through "media". But I don't really care about his ad-relevant personality matrix, I just want the endpoint. The profile metadata is the aspect created and mistreated by FB, and abused by CA. I suppose scraping the proposed hypothetical API would be akin to getting a large list of valid emails, but it's not as useful for targetted agitprop.