In some of the cases, the athletes had e. g. XXY chromosomes, i. e. even in the strict biological classification, they did not fit into the male-female scheme. But there had been cases of biological women (i. e. they had XX chromosomes) with unnaturally high testosterone levels who had been excluded.
So perhaps we need to revisit participation rules also for this reason. IMHO I find it unfair that people with XX chromosomes are excluded just because their physiology gives them an advantage. Isn’t that what sports is about? Physiology gives athletes an advantage over average people when competing.