I think it's interesting when the word "menstruator" is justified by the claim that women past menopause do not menstruate. I think this illustrates one of the creepy purposes of using dehumanising terms such as "menstruator", which is to separate women into different groups and pretend like those groups have nothing in common with each other. It's basically a "divide and conquer" strategy, splitting women up into different groups and placing them in different silos, socially, politically, linguistically. And yet, women past menopause are the same group as women who menstruate, just older!!!!!! You can't be in menopause unless you are female.
The dehumanisation is not only in the redefining of the words 'girl' and 'woman' and 'female' and their replacement with "menstruator" "cervix-haver" and "pregnant person." It's also in the pretense that the only thing that's important about you is today's biological function, and the pretense that you can be categorized solely on the basis of this particular function, as if all the other aspects of being female are something totally unconnected, as if we are all little lego toys, with parts that can be disconnected in space and time.
But in the real world, the baby born with a uterus is the same person as the adolescent girl a few years later who gets her first period, who is the same person as the young woman a few years later who gives birth, who is the same person as the woman 20 years later who undergoes menopause, who is the same person as the woman 10 years after that who gets uterine cancer, who is the same person as the woman who gets a hysterectomy for that uterine cancer. We're not just female in the one moment where a man looks at us and says, "menstruator." We're female for the entirety of our lives!