A lot of talk on this issue is fantasy, and I'm sure the well-made point about moving the Overton window is right. Let's not forget, though, the sheer ignorance and lack of intellectual curiosity and common sense that so often runs through discussions of topics like this.
A not insignificant number of people think women have two holes 'down there', not three. This is of course related to the view of the female body as a series of holes, a passive vessel waiting for a male to make use of these holes.
There is very little understanding of how complex women's bodies are or how they develop. I often see a casual assertion that all embyos start off as female and then some (the favoured half?) develop as male, very much implying that this is going to be the more complex of the two options. This is nonsense. All embryos develop in the same way to begin with, but from a weeks after conception, male embryos develop in one way and female embryos develop in another way. Female bodies are far more complicated than male ones, especially after puberty.
It doesn't surprise me that some people think a uterus could just be put into a male body and would work, because they have no grasp at all of all the complex inter-related systems that are involved in female bodies even when not pregnant, never mind the massively more complicated changes that happen when a woman is pregnant.