I worked on the trending product. This did not happen. The whole thing goes back to one guy complaining now that he couldn't pick Breitbart for the highlighted slot for some story because it wasn't on the list of approved sites. And this list is actually available here https://cdn.ampproject.org/c/newsroom.fb.com/news/2016/05/in... Of course no one ever asks why he wanted to pick a controversial site to highlight instead of say a boring straight forward wires service report like the AP.
Of course the story still appears, and the Brietbart could appear in slots 2-N by the personalized ranking algorithm, so it's not like it surpressed. He just wanted to shove it into the I personalized slot 1 where everyone would see it.
FWIW FP briefly used an embedded facebook widget, and a nonzero percent of their livefyre users logged in via FB.
It did little to nothing to stop abusive comments. The HN crowd cares a lot about what sort of history follows around our names and our handles. Many others, both in the western world and abroad, do not.
But suggesting people engage instead on Facebook brings a whole new set of ethical concerns. (1) Facebook manipulates users. (2) Facebook reorders feed. (3) Facebook would lower priority of conservative news sites. And lets not forget that Facebook is probably outsourcing moderation anyway. Plus, Facebook commenters can be just as bad as regular site commenters.