I believe they're imagining a system where any comments on Facebook/Twitter etc would be essentially mirrored. Perhaps a webhook of sorts that pushes comments

I believe they're imagining a system where any comments on Facebook/Twitter etc would be essentially mirrored. Perhaps a webhook of sorts that pushes comments discussing a link to the link itself and would then be imported into their own comments database. Of course, I doubt Facebook would do this seeing as there's no tangible benefit to them