Those incidence numbers strike me as implausibly low. I happen to know two transpeople fairly well by completely random chance. One is good friend of my (now adult) kids, whose parents are also friends of mine who I met through work, the other is an adult child of my girlfriend.

Unless you hypothesize that for some reason I befriend people who have a vastly increased probability of having trans offspring, numbers like 1:10E4 give me a 1:200000 of being in this position. I would generously assume I know 25 people as well as I know these people, so the probability of finding two in that group who are trans would be 1E-4251E-4*24 = 0.000006. Tiny.

Now, in a world with a few billion adults in it there are going to be a few tens of thousands of people like me, who know more then one transperson from completely unrelated means, but it would be interesting to know if anyone else here does. I'm pretty sure people in my situation are not as rare as those numbers would indicate.