Well....it comes down to this. Once you have Trans-Men (former females) who've done all the surgical stuff, hormone business, and mental therapy to get over the 'hump'.....then what you have is a man who still has potentially the functions to get pregnant. At some point, these 'men' will find some method to get pregnant, and ease into a situation where a man delivers a kid in nine months.
Medical science will just keep its mouth shut, and most logical people will suggest that it was the woman who conceived and delivered.....not the Trans-Man.
So BP's need to exist somewhere in reality....if you need to make sense out of this. All this hormone stuff affecting the kid delivered? Well....you can't say this until you get a couple hundred delivered and some have 'problems'.
I know it's tough to understand, but this is reality in 2022.
Logically, you will ask....shouldn't non-birthing-people (former men who got over the 'hump' to become a Trans-Woman).....now exist as well? Any day now....NBP's will be designated and will exist for the official record.