Someone asked in the comments that Zack clarify wtf the claim is, and Zack posted this abstract:
Does this help? (159 words and one hyperlink to a 16-page paper)
Empirical Claim: late-onset gender dysphoria in males is not an intersex condition.
Summary of Evidence for the Empirical Claim: see "Autogynephilia and the Typology of Male-to-Female Transsexualism: Concepts and Controversies" by Anne Lawrence, published in European Psychologist. (Not by me!)
Philosophical Claim: categories are useful insofar as they compress information by "carving reality at the joints"; in particular, whether a categorization makes someone happy or sad is not relevant.
Sociological Claim: the extent to which a prominence-weighted sample of the rationalist community has refused to credit the Empirical or Philosophical Claims even when presented with strong arguments and evidence is a reason to distrust the community's collective sanity.
Caveat to the Sociological Claim: the Sociological Claim about a prominence-weighted sample of an amorphous collective doesn't reflect poorly on individual readers of lesswrong.com who weren't involved in the discussions in question and don't even live in America, let alone Berkeley.
so this is a two-hour post about Zack's arguments with unnamed Bay Area rationalists. Today, in posts that should have been a Discord chat.
(the paper he names is a Blancharding ramble)