Alcohol consumption statistics do not show a rise in consumption corresponding to the gestation of the children who now make up the rise in Autism and ASD. And if you don't think alcohol was as much a fashion accessory as it is now, I suggest you watch a few old movies.
It's an interesting hypothesis, but like any hypothesis it makes predictions, like that per capita alcohol consumption would rise, and that states with the highest alcohol consumption would also have the highest level of autism and ASD. Indeed, alcohol consumption dropped a bit in the 1990s relative to the 1980s, yet it's in the generation gestated in the 1990s that you see the big rise in Autism and ASD, and Utah, with the lowest level of alcohol consumption of the 50 states has one of the highest Autism/ASD prevalence rates.
The data just aren't there to support it.
Alcohol Stats
Autism Stats