Gosh, I’m getting tired of bringing this up…
One of the most common reasons for ambiguous gender in XY humans is malfunction of the male-determining system. The most extreme variant results in a human being with a vagina, breasts (often of large size), and not a hint of penis, scrotum, or facial hair. Prior to the discovery of chromosomes and their role in sex determination no one had any clue these folks were “supposed to be” male and an affected individual was seen as a woman whose uterus failed to develop. Raising such a child as a boy because of the chromosomes would cause confusion, not prevent it.
In fact, the international Olympic committee, which requires chromosome typing of all athletes to prove gender, actuallly does recognize athletes with this disorder as females.
There are various other ways for the system to go wrong, too. Yes, what the chromosomes say is one important factor - but it’s not the only one. If the child is just a little outside the norm that’s one thing, but in the extreme cases there may be no way to determine which way the kid will lean.
One instance that got publicized involved a woman who goes by the name “Tula”. Tula is definitely feminine in appearance - she played a Bond girl at one point, spending considerable time on a movie set in a skimpy (for the time) bikini with no one having a hint this person might be outside the normal of “female”. Tula, however, was raised as a boy, and in fact has an XXXY pattern of chromosomes. Clearly intersex at birth, raised male to “avoid confusion”, in the teens decided she was really a girl after all, had some surgery (on her own decision) – yes, it is confusing.
Myself, if I had an intersex child I’d prefer to wait on the surgery. Certainly, there are some cases where, in addition to unusual formation of the genitals there are issues of being able to perform necessary bodily functions and surgery is required… but the idea of nipping and tucking for aesthetic reasons is repulsive to me. It surgery done for the comfort of others, not for the benefit of the person being cut upon.
It’s even possible that an intersex child may decide to remain intersex, just as some now-adult conjoined twins refuse to be separated even though it is now possible to cut them apart
I think it’s more likely an intersex teen would prefer a definite gender… but if the surgery is put off to the teen years and the child participates in the decision then, not only is the resulting body more likely to match the gender the child feels in his/her head, but it’s also surgery done with the consent of the patient, and with greater awareness of why this pain and healing is occuring. There’s a world of difference between telling a child “you came out unfinished so we made you a girl” and the person involved saying “I don’t care if I have this thing that looks like a dick - I’m a girl, can we trim this thing down?”