Science has shown that there is more than two combinations of X and Y chromosomes. So if you went by chromosomes alone, there's more than two sexes. And if you go by phenotypic categorization (secondary sex characteristics, like tits, balls, dick, vagina, voice, height, etc), there's a multitude of sexes and male and female are just categories. Again this is well-documented in scientific literature, it's biology 101.
But then "the right" also mix in references to gender as banned. Gender, as every half-educated person knows by now, is different than sex: gender is social expression, sex is biological expression. Gender is your clothes and hair and voice and name, sex is the junk in your pants.
But the "right" is basically saying: "Hey, science is wrong! And these weird leftists are wrong! Sex determination doesn't matter, gender determination doesn't matter. There's only two things in the world, ever, and we call them male and female. Science and society and logic and reason and everything else can get fucked."
It's political psychosis. Hate-filled zealots who are so hell-bent on imagining the world in a more simplistic way that they literally want to re-define reality to fit their wishes. It's the book Nineteen-Eighty-Four, being enacted in real life. This isn't a joke or hyperbole, this is literally what's happening. They're creating a government of insanity.
Since they can't literally stop people from having all kinds of combinations of chromosomes and primary/secondary sex characteristics, the next step will be what the Nazis did, which is to round up anyone who doesn't fit a "normal body" and incarcerate them or force them into medical procedures to "fix them". (we actually did this in the past, too, not just the Nazis)
But before we get there, the first step is to force the government to perpetuate the psychosis so they can say it's official, and then people will swallow it easier. They are betting that we won't do anything. And we won't.