Several points the article makes:
1. One of the X chromosomes contains the SRY gene normally attached to a Y chromosome, so it is not a case of normal XX chromosomes.
2. The testicles of such individuals are usually underdeveloped, something an alert pediatrician should pick up in the individual's childhood.
3. The people in question are invariably sterile.
4. The article characterizes XX males as mostly "typical boys and men," which I take to mean most of them are not transgender.
5. The condition affects about 4 or 5 in 100,000 people, so it is rare, much rarer that the 3 in 1000 who certain polls say are transgender.
In contrast, most transgenders have normal chromosomes, and are not sterile, but just psychologically feel they are of the opposite gender.
Since such individuals have a perfectly well functioning body, it would make no sense to me to mutilate such a body if psychological treatments were available to correct the delusion that they are of another gender.
This is much the point of view taken by Paul McHugh, the former head of psychiatry at Johns Hopkins (where gender-reassignment surgery was pioneered, but abandoned after 10 years, because it wasn't solving the patients' problems).