I have a similar story! My son was diagnosed with autism at age 2.5 and the testing indicated average IQ. I didn't really care about that at the time (like you!) and was in fact happy to hear he was not retarded! Fast forward 3 years and the school did another set of testing and informed us he was in fact gifted. (It was one of the few 100% positive meetings we had had with the school...they were so proud...) Then when he was 7, the school did more testing and we found out he was extremely gifted. We contacted Davidson because, like you, had never heard of 2e. He became a young scholar and we hoped Davidson could be a help in our roller coaster journey.
As for autism affecting his giftedness, I see that as mostly positive. He thinks outside he box (or the polydodecahedron as one teacher said) which will serve him well in the future. He has had lots of therapies and we can compare notes if you'd like. Right now he is in 4th grade in a gifted school.