This isn't a suprise. to any of us who have been on the Internet for most of our careers prior to the Web. Email relationships, technical list relationships etc. are older and consistent. Since social networks favor the oldest connections, it is not surprising that the dark net still dominates communications and link power. How the structuring of relationships work out past my generation should be a follow-on study.
How this affects so-called "disruptive innovation" is a question worth asking as that idea is increasingly viewed as corrosive to society.