Overall, the article is a step forward. But the approach seems to depend on the assumption that autism is actually increasing: "When Chez was in medical school in the 1980s, he was taught to expect autism in about one child in 10,000. Now it's about one in 150. That means that the majority of people with autism today haven't grown up yet – and little is known about what their lives will be like when they do."
It seems clear that there are plenty of adults on the spectrum, many of whom have never been officially diagnosed. It's still up for debate, but the evidence seems to indicate that the growing numbers of autistics is due mostly to awareness and increased attention to diagnosis. "Most of the people with autism in California are 3 to 18 years old," I doubt that.
One problem I have with the article, is that it's unclear whether it refers only to people who fit the diagnostic criteria for autism, or whether Asperger's is included.