I think you are confusing 3 very different concepts in this article.
1. Gender Identity
2. Gender Expression
3. Biological Sex.
Gender Identity is who a person is. Gender expression is how they prefer to express their gender. Biological Sex is a totally different thing.
For example, I personally know a little boy whose favorite color is pink. He is still a boy, he identifies as a little boy, but he loves the color pink. Liking pink is a color associated with girls. But he is not a girl, he is a boy. Liking pink is an example of gender expression, not gender identity. He is still a little boy, he identifies and sees himself as a little boy, but he still likes pink. I have no idea what is biological sex is, because I feel it is inappropriate to wonder about another person's genatallia. Boys can like pink, and gender theorists are not here to enforce narrow sterotypes, nor are trans gender people here to do that.
Here is another example, I have a close friend is a trans woman, but identires as a butch lesbian. She engages in a lot of behaviors that are often associated with male gender expression. Her hobbies are playing DND, she works as a computer programmer, she usually wears jeans and simple black T-shirts. However I can tell you she is very much a woman like any other butch lesbian. Her gender expression is very masculine, her gender identity is female, but her biological sex is male. I also know a lot of cis butch lesbians, who are no less women than my own femm-self. Dressing or acting the way they do makes them no less women. It changes their gender expression, with their gender identity. Here is another example, I am a woman. I know I am a woman, and I live as a woman. If suddenly started dressing as a man, even took a man's name and pronouns, I wouldn't be a trans man, because deep down I still feel like a woman. I would be a cross-dresser, because though my gender expression would have changed, I am still a woman and I identify as one. So even though I might change my gender presentation, my gender identity does not change because I am still me. Now my biological sex matches my gender identity, therefore I am a cis woman. I agree that feminists have long fought for nuterality among gender expression. That's great. But flexability and nuterality among gender expression doesn't change gender idnetity. The trans community argues for respecting gender identity, but my experiences is they totally support any flexability among gender expression. No one thinks that a woman playing soccer should actually be a man, that's silly. Little boys can like the color pink and even wear makeup, it doesn't make them women. Infact all the trans people I know fight for flexibility in gender expression without it changing identity. Trans women want to be able to do whatever they want to without their gender identiy being challenged, at least the trans women I know. No one is trying to force someone else to change their gender identity to match their gender expression. They are different concepts. We can respect people's gender identities without forcing people into sterotypes around gender, because gender expression, gender identity, and biological sex are all totally different things.
