They seem to be moving the goalposts a bit:
When the biology gets too complicated, some point to differences between brains of males and females as proof of the sexual binary.
It's the genderists who've been going on about male and female brains, but now they're trying to say it's the non-believers in genderism who've been pushing this idea.
But a half century of empirical research has repeatedly challenged the idea that brain biology is simply XY = male brain or XX = female brain. In other words, there is no such thing as “the male brain” or “the female brain.”
It's almost as if they haven't been listening when we've repeatedly been saying that.
Let’s just take the most famous example of sexual dimorphism in the brain: the sexually dimorphic nucleus of the preoptic area (sdnPOA)...Throw in the observation that the sdnPOA in gay men is closer to that of straight females than straight males, and the idea of “the male brain” falls apart.
So have they changed their tune about sexed brains now? It's so hard to keep up with the constantly shifting positions.
For some properties like brain volume and connectivity, trans people possessed values in between those typical of cisgender males and females, both before and after transitioning. Another study found that for certain brain regions, trans individuals appeared similar to cis-individuals with the same gender identity. In that same study, researchers found specific areas of the brain where trans people seemed closer to those with the same assigned sex at birth. Other researchers discovered that trans people have unique structural differences from cis-individuals.
Sounds like an inconclusive mess to me.