Beach that's a fair point. I haven't, I admit, read Woman Hating; and there Is no knowing what Dworkin would have made of the current trans debate, or whether she would have amended her theoretical premises in response to it. But Dworkin consistently argued against there being two discrete biological sexes. Indeed, that contention was a fundamental premise of her project.
She wrote:
"We are, clearly, a multisexed species which has its sexuality spread along a vast fluid continuum where the elements called male and female are not discrete."
A more salient quote however is this:
"You think intercourse is a private act; it's not, it's a social act. Men are sexually predatory in life; and women are sexually manipulative. When two individuals come together and leave their gender outside the bedroom door, then they make love."
This quote contains a contradiction. She is on the one hand asserting intercourse to be a social act, governed by a false identitarian dichotomy; but she is on the other hand postulating the potential for it to be an asocial act in which gendered identities can be cast off like clothes.
Dworkin was a child of the sixties, and therefore a hopeless idealist. For all her intellect, she brought into the ideas of cranks like Reich. She thought patriarchal power and sexual repression was the root from which all other totalitarian ideologies stemmed. If only the burdensome carapace of male and female could be cast off and a genderless eroticism released, then not just patriarchy but political violence itself would end. In that she was wrong.