I think you're missing some key nuance. Zuck mentions the research as industry leading because the research has uncovered something deeply embarrassing for Facebook.
It's relevant that this is "industry leading" because no one else has done this work. The implication is that the same patterns at Facebook are likely true with other forms of media.
Other researchers don’t have free access to the same data, so their own research is industry leading by default :) Anyway, the term is intended to be used as PR to appeal to the media, I assume, than to be really accurate.
It's relevant that this is "industry leading" because no one else has done this work. The implication is that the same patterns at Facebook are likely true with other forms of media.