Sourced material?
Numerous documentaries on transgender over the years had the men saying they still wanted women, transgender men frequently become “lesbians”, Bruce Jenner has stated be was NEVER attracted to men.
Thinking you are supposed to be a woman is a separate mental issue from thinking you want men sexually. Also we are talking about preteens and teens who are experimenting with sex. No reason to believe kids of opposite sexes with opposite genitalia won’t screw around in showers in school.
Very few transgenders ever change their genitalia. What did you think transgenders do with their penises, did you think they are all gay men? They are not.
Maybe I can help. This is from Paul McHugh, University Distinguished Service Professor of Psychiatry at Johns Hopkins University:
Thanks to this research, Dr. Meyer was able to make some sense of the mental disorders that were driving this request for unusual and radical treatment. Most of the cases fell into one of two quite different groups. One group consisted of conflicted and guilt-ridden homosexual men who saw a sex-change as a way to resolve their conflicts over homosexuality by allowing them to behave sexually as females with men. The other group, mostly older men, consisted of heterosexual (and some bisexual) males who found intense sexual arousal in cross-dressing as females. As they had grown older, they had become eager to add more verisimilitude to their costumes and either sought or had suggested to them a surgical transformation that would include breast implants, penile amputation, and pelvic reconstruction to resemble a woman.
Further study of similar subjects in the psychiatric services of the Clark Institute in Toronto identified these men by the auto-arousal they experienced in imitating sexually seductive females. Many of them imagined that their displays might be sexually arousing to onlookers, especially to females. This idea, a form of “sex in the head” (D. H. Lawrence), was what provoked their first adventure in dressing up in women’s undergarments and had eventually led them toward the surgical option. Because most of them found women to be the objects of their interest they identified themselves to the psychiatrists as lesbians. The name eventually coined in Toronto to describe this form of sexual misdirection was “autogynephilia.” Once again I concluded that to provide a surgical alteration to the body of these unfortunate people was to collaborate with a mental disorder rather than to treat it.