What I would suggest as a pathologist who deals with diagnosing these: the incidence of differences of sexual development is somewhere between 1 in 1000 - 4500 births. So this policy will not unlikely diagnose someone with a DSD who didn't know.
Women with DSD on averave have a higher testosterone level. Testosterone generally makes you better at sports. The Olympics select for the very best athletes.
In other words: the Olympics are selecting for women with DSD, so once you start doing 100% testing you'll find an incidence far above that of the general population.
If you have male chromosomes, but you have woman genitals, then that’s a proof that you are testosterone insensitive. In other words, testosterone doesn’t make you better at sports at all. The topic is way more complex than this.
There are proofs that male chromosomes are beneficial for example in boxing for women, but it’s not because of testosterone as far as we know. In almost every other sport, it’s not beneficial at all, and even negative because of the mentioned testosterone insensitivity.
If Semenya had been categorized according to his sex, he wouldn't be considered amongst the very best athletes. He is basically a middling standard 800m male runner who has been able to make a career on the back of what is essentially an administrative error.
Talent scouts specifically sought out males like Semenya who were erroneously registered as female at birth, knowing that their male physical advantage would give them an edge in women's competitions.
The specific condition he has (5-alpha reductase deficiency) is one that only affects males, conferring upon them internal testicles and a micropenis. But male development, including all the testosterone-driven advantages that distinguish male and female athletic performance, is otherwise normal.
His gold medal in the 2016 Rio Olympics women's 800m, along with silver and bronze being taken by two other males with similar conditions, is the reason why World Athletics (then the IAAF) and, later, the IOC started to move policy away from eligibility by identity documentation to empirical testing of sex advantage.
The policy change discussed in the linked article wouldn't have happened without athletes like Semenya taking advantage of the previous flawed policy, to the detriment of female athletes.
Caster Semenya is a woman, not sure why you're referring to her as him. The fact that she has a potentially unfair advantage due to her unusual genetics in women's competitions doesn't in any way make it fair to refer to her in this way.
If you look at accounts from Semenya's early life there is evidence against his account of growing up as a girl. For example, there have been school photos published showing him wearing a boy's uniform near to a group of girls who were all wearing girl's uniforms. His former school headmaster, when interviewed years later, said he thought that Semenya was a boy and was very surprised to hear that he was now competing in women's athletics.
And of course he would have gone through male puberty, not female puberty. This would have been obvious then, and the result of this is obvious now if you see him in interviews. Male-typical build, male-typical vocal tone. Even his now-wife assumed (correctly) that he is male when she first met him.
Semenya has to double down on this narrative that he is a woman otherwise he will have to admit that his successful sporting career as a woman will have been a lie.
Even if you believe that it is the case that she lived her early life as a male, at the point that a person has made it clear that they have some preferred pronoun/is trans would it not just be disrespectful to intentionally refer to them counter to that?
It will certainly do that. Previous attempts at this (the Olympics did genetic tests from the 1960's through the 1990's, other organizations have done similar tests into the present) always did wind up discovering cis women raised as women from birth, with female presenting genitalia, who failed whatever genetic tests they were doing. At least one of these women even went on to give birth to a live human baby! You would think that would prove that they actually were a woman, but their medals were still kept from them. They were still driven from the sport, branded as cheaters, etc. Because someone who was so much better than the rest can't really be a woman, they have to be cheating somehow, they have to be a man.
In fact, I'm not aware of any genetic testing program ever catching any deliberate cheating, only people who were raised from birth as women. The very first example of this, (1), Dora/Heinrich Ratjen (2) seems to have been an intersex person who was definitely raised as a girl from birth who was a bit confused about what their body was doing. But all the way back in the 1950's when their 1936 Olympics became a big deal, we have lurid tales in the English language media of deliberate cheating that don't seem to have been supported by anything that Ratjen ever did.
I wouldn't call it cheating. But I have no trouble drawing lines that exclude some people, if that levels the field for a bigger group. In this case the female olympics would soon be known as the intersex olympics given the selection pressure. I can understand the decision to make the competiton more interesting by barring intersex people. No need to frame it as cheating though.
Since we don't actually do genetic tests at birth, this would only ocurr in the context of national qualifying, think about what the experience of someone who trains to be good enough to qualify for the Olympics, then gets this test and is told, "Sorry, you aren't really a woman. Too bad. No Olympics for you. Sorry you wasted all those years training."
How else should the person who just got that information interpret it except... Sorry, you're not really deserving, even though your score qualifies you. And what do call someone who has a score that qualifies but doesn't get to go?
And there are far more of people with this experience than the experience of being born and treated by society as a man and becoming an Olympic athlete as a woman.
When I’ve researched this it’s turned out that among elite athletes it tended to be a bit higher since some of these intersex conditions can confer benefits
This is a gross (literally) misunderstanding of the entire topic
The ruling covers a lot of the nuanced cases, including rare DSDs that may never even apply to Olympic athletes
The tests DO NOT check for genitals, and that is irrelevant to the decisions! It's a cheek swab that checks genetics.