tbh I'm not really seeing what the big fuss over the book aimed at 15+ is (other than the 'people with vulvas/people with prostates'
bull, which is awful).
Whether you like it or not, some teens are going to be having sex and it's better they know how to do it safely. Lots of studies (mostly in Scandinavian countries, I think) show that kids who receive the most comprehensive sex education are the least likely to have poor sexual health outcomes. Whereas the ones who have the least (Bible belt areas) are rife with all sorts of horror stories like shellshocked teen parents who still believed their parents' lies about the stork and had no idea what they were doing or that it could lead to pregnancy. Kids who don't receive sex education are also more likely to be victims of abuse, because their ignorance and naivety makes them an easy target for predators.
Ffs, I went to a private Christian school that gave us like half an hour of very basic, undetailed sex ed, but even then, they had us practice putting condoms on a banana and gave us a couple to take home. That was in year 10, so 15/16 years old. Absolutely no one immediately ran off and had sex just because they were there. And they weren't there for long! Unsurprisingly, most of them got used as water balloons or slingshots at lunch that day.

But surely if anyone actually needed them it's better they had them, right? (And hardly anyone did, as far as I'm aware anyway. I only knew of one (maybe two if a rumour I heard was true) girl/s who lost their virginity that year, everyone else not until at least 17 or older (mostly older.)
Again, the gender woo language sucks, but that's the only problem I'm seeing. It's the kids who don't read or learn on their own who are the most likely to do ill-advised things at younger ages. The school providing the information is better than the teen seeking it out on their own or worse, not seeking it out at all.
It's perhaps worth remembering that when only heterosexual sex is covered in school sex ed, LGB kids have to seek the information out on their own, which can lead to a higher risk of grooming/abuse. It didn't happen to me, but I know I was lucky not to run into anyone with bad intentions. I certainly spent a lot of time in adult online spaces, very much underage, because there was nowhere else to go. I definitely stumbled upon adult content 2-3 years younger than I otherwise would have, because there were no youth-only LGB spaces readily available when I was a teen.
And it's also (unfortunately) worth remembering that, thanks to the prevalence of kids with unregulated smartphone use, and anal sex having become pretty much mainstream in straight porn nowadays, that it is no longer an issue that doesn't affect straight teens. It was on this very thread that I recall reading a horrific news story about a teen girl being injured by some dumbfuck boy who thought he could just ram it in with no lube or prep because his only sex ed had been porn.
Sorry but I'd much rather they learn how to do it safely in a book if it prevents even one ,more case like that from happening.