I don't agree. Allowing someone to list their relationship status on their otherwise-non-dating-site profile is a far
far cry from providing tools and UX to help people match with others they might be interested in.
Certainly people have found romantic partners on FB in the past 15 years, but I would view that as in spite of the lack of dating-related features. Up until now, FB has not been geared toward or especially useful as a dating platform, especially given the availability of dating apps that actually fill that niche.
I think FB Dating has the potential to be way more successful to a mainstream audience than nearly any dating app built to date, though.