No, it's not a regressive view. Whether you're a man or woman is determined by whether you're male or female, which is determined by your body parts, whether big ones like your genitals, or really really tiny ones like the SRY gene. It's all body parts.
The regressive part was saying that people couldn't do certain things because of those body parts. It wasn't the body parts stopping women from getting jobs, owning property etc, it was the patriarchy. Yes, the patriarchy exists because men were stronger and faster, and so better able to subjugate women, but the regressive part was carrying on that power structure into the modern day.
No obviously your biology determines whether or not you can do certain things. I can't grow or feed a baby for instance, I lack the relevant plumbing. But again, thats not regressive, thats just basic science.
Transwomen aren't women, they're men.