Yes, it's for us to know ourselves and assert ourselves. That said, for me a diagnosis is helpful b/c I have difficulties with lifelong invalidation. Interestingly nobody at my ASD support groups or here have invalidated me... yet. Given the ASD stereotype remains: male, "cold", externalizing --- and I am none of those, I am still on the side of cultural invalidation. The diagnosis is a mental "leg up".
@Nic, I like to imagine that you set in motion something for that evaluator (or her sphere) that will help other ASD folks be correctly assessed. Enough invalidation for us already!!