You ought to read my comment carefully. Singal (not Signal) and Soh are "major figures in transphobia", and Molyneux is a pro-fascism campaigner. The former two (Singal, Soh) are advocates of "gender essentialism", and the latter travels internationally campaigning for the "race essentialism" and policies based on that. As you're aware of both of (Singal,Soh)'s first names already, is it a fair guess that you're already familiar with some of their transphobic work? Perhaps then, that is a good place to start. As just one example, Soh is actually so committed to gender essentialism that it's led her to advocate the approach that: your assigned male at birth teenager who tells you that they're trans and requests to transition is actually gay in my opinion so being affirming to them about that is homophobic ( from her article in reactionary online journal "Quillette").

Soh will of course try to dress that horrific construction from her article up in professional-sounding language, but our duty is in fact to address the thrust of her argument, not whether she attempts to frame it in polite language. You might also recognize Soh from her work in the atrocious Matt Walsh "documentary" that pretends to be about women but is entirely about invalidating trans people.

To make this more clear: Soh's need to provide an explanation for femininity in a person who is assigned male at birth while denying the validity of trans people is only necessary for a person operating from a bioessentialist lens. The need in Soh is so strong that it leads her to make totally unfounded and ridiculous claims in that article, and it also drove her promotion of the discredited (and retracted!) pseudoscientific 'Rapid Onset Gender Dysphoria)' invented by Lisa Littman.