Without reading the article, I'm going to say "full of dudes."
Over the last week, that pit has consisted of “egirls only,” “hot egirls only 18+,” “only hot girls 420,” “[Name redacted’s] feminist island 2/2/2 girls only,” and over a dozen of other Overwatch groups purporting to be all or mostly women cropping up every day. I joined every one I could find.