I think the OP meant, "If AS became the dominant phenotype, would it happen more slowly among women than among men?"
I don't think, personally, that AS could ever become dominant; NTs are too versatile. The generalists are more likely to survive disasters than the specialists; and while it's beneficial to a population if there are autism spectrum genetics in that population, a population being entirely autistic would be too unbalanced to be adaptive.
So I don't think it would happen at all. We should just reach a balance point at which the number of autistic people in a society is most beneficial to that society. I'm thinking that that point is somewhere around 1-2%, but not much higher than that. Ultra-specialized people are fine, but who does the general work--producing food, running machinery, coordinating the society? You don't need that many specialists; and anyway, if you have too many autistic people, you increase the number of autistic people that the society has to support, which it can only do up to a certain point... eventually the benefits of having somebody who has a certain specific low/high skill profile to do a certain specific job will balance out the costs of supporting the disabilities involved with that skill profile... at that point, the people who can't find well-paid jobs because the specialized niches left over don't fit as well will start to have fewer children because they can't support them as well. So it's self-limiting once the available societal roles run out. Theoretically if everyone were autistic it would work better than if a very small number were; but there's no way you'd get anywhere close to half. People who need things most people don't will tend to be at a disadvantage, and that disadvantage is probably enough to keep them from ever becoming the majority. The only way I could see it happening is if other neurodiverse people also increased in number, allowing specialist roles that don't fit most autistic profiles to be filled too. You'd still have a minority of autistics, but you'd also have other non-NT types increasing, to the point that NTs may still be the largest group, but total no more than a tenth of the population... A world like that would be very interesting and extremely interdependent. I think it would require technology we don't have right now.