This should serve as a lesson to women everywhere that to conservatives, the definition of "trans" is flexible, and that someone is a "woman" only as far as it is politically useful to conservatives.
Look at the attack on the two Olympic athletes this summer. They were cisgender women, but they didn't meet western white beauty standards, and the right needed to find some "trans" athletes to attack, so they labeled cis women trans and demonized them. They still reference them in speeches.
Or these girls in this ad. Just some random cis girl athletes, but it was politically useful to label them trans, so they did.
As the culture war moves ever-more extreme, the definition of "trans" can always be expanded. Remember, 90% of cisgender women are crossdressers according to the traditional definition of the word. 90% of cisgender women regularly wear clothes that would literally have gotten them arrested in many parts of the US only half a century or so ago. It was literally illegal for women to wear pants in many areas. And as the push to confine women to ever-stricter gender roles marches on, any woman that doesn't meet this ever-narrowing standard of beauty can be labeled "trans" and have their rights stripped away.
Are you a woman athlete who looks a bit 'masculine' from years of participating in a contact sport like boxing? You're "trans" and deserve to have your civil rights taken away.
Are you a woman who works in a traditionally male career field? You're "trans" and deserve to have your rights taken away.
Do you wear anything other than dresses, skirts, and other traditionally female clothing? You're "trans" and deserve to have your rights taken away.
Do you want to have any independence at all, have your own bank account, and have any role in life other than daughter, wife, and mother? You're "trans" and deserve to have your rights taken away.
The attack on trans people is a perfect wedge for the right. There is no hard definition for the word "trans," and it can conveniently be defined ever-wider to confine women to ever-narrower ranges of acceptable behavior. When you hear hard right reactionaries talking about declaring being trans illegal or waxing about putting trans people in mental institutions, remember that it wasn't that long ago that cis women that showed any degree of independence were also institutionalized and lobotomized.
In the minds of many hard-right conservatives, 90% of women today are acting in ways that are fundamentally in contradiction to the role of their sex. In their eyes, most women are transgender. And while the narrow edge of the wedge is targeting people who actively seek out overt gender transition, that isn't the real end game.