I personally think a lot of autistic people are not diagnosed for having these "atypical" traits. By "atypical", I mean traits that haven't caught the eyes of neurotypical doctors and/or writers to the same degree. I know way more autistic people that are "hypersexual" and/or touch craving than asexuals and/or touch avoidants, two of which got way more attention in both medicine and culture.
Yeah, the diagnostic system was adjusted with the publication of the DSM-5 in 2013.
Asperger's Syndrome was rolled into Autism Spectrum Disorder and Autism got three levels.
Little bit of skimming articles seems to say that the levels are based on need for support, higher being needing more.