"the term 'autism spectrum disorder' is pejorative because autism isn't disordered"
Buddy I have some bad news for you about medical nomenclature
The takeaway here is, medical terminology is often pejorative towards the medicalized. Autism is not exceptional in this regard.
If you removed all stigma from autism, and only autism... a lot of autistic people would still experience ableist stigma, because we're multiply disabled. And we'd know how little the autistic people who'd now claim they're not disabled would think of us.
(This is not exclusive to autism. I'm generally opposed to disability exceptionalism—it does not help us as a coalition if certain people argue for respect on the basis of "but I'm not actually disabled" if that leaves everyone else up a creek!)