Sounds very strange. They’re boys with androgen insensitivity, so they don’t develop...penises? How do they develop uteruses, labia, and breasts? They don’t have the genetics to grow those things.
No, actually the changes in morphology from female-form to male-form are controlled by the response to androgens normally created by the presence of a Y-chromosome. If other genes cause a complete lack of androgen receptors, the body develops in the female form. Such people typically don’t get called “boys” because we don’t do genetic tests to determine the sex of children, just look at them at birth.
There are milder forms of androgen insensitivity in which the child develops normal male characteristics, but is infertile, or (quite rare) if born “intersex” not looking properly male or female. In the latter case, the child has typically “assigned” a female sex by surgery — giving rise to the mythology among the advocates of transgenderism that sex is assigned — and surgically modified to match. (Incidentally, the sole instance of sex-change surgery the Russian Orthodox Church accepts as legitimate is reversal of this erroneous “assignment”.)
The point is that although an XY pair codes for having a penis, the way that code is implemented involves response to androgens. (In the first instance DNA codes for proteins, how the mix of proteins encoded translates into cellular structures, tissue organization, and body form is still largely a mystery.)