Well, we have decided to disclose his diagnosis to our insurance company so that we can continue to get him therapy. This is a big deal for us, disclosure. Not because we are not open, but once you disclose the information, it is no longer in your control. For example, once our insurance carrier knows they will share his info with all future insurance he will have. Also, the school will probably know at some point and it will follow him through high school and into college even. I hope he is never discriminated against, or denied coverage based on pre-existing condition.
As a parent you try to make the best decisions for your kid. You have to weigh current benefits against future needs. The future is a risk and a gamble. But if in the future insurers decided to deny benefits to individuals with ASD based on pre-existing condition there would be a lot of outcry since ASD affects a large population.
You want to give your kid every possible opportunity to succeed in life.