[coldtea]

>If the "assortative mating" hypothesis were correct it would mean that in the past people with ASD would have been having children with normies, for lack of a better word, and then due to some vague advancement in society are now instead choosing to mate with people who have more similar traits to themselves.

You say "it would mean that X" which makes one expect you'll mention some X that is implied by the hypothesis, but you're you're merely re-stating the assortative mating hypothesis.