Yes, Autism and other developmental mental health issues are something we understand as diseases or problems. But when you dissect all that Autism is, it is just a neurological brain somewhat behind on functioning. There are plenty of people who exhibit autism like behaviors, but not to the degree or whatever that Autism does. Autism is noted as a spectrum for a reason; there is high functioning all the way to low functioning. Behaviors in autism result from many unwanted stimuli and many autistic children do not know how to or even that it is appropriate to get through the struggle and cope with it. As normal adults exhibit their own coping mechanisms, it is more of a struggle with those who don't have this capability - which is Autism, essentially.
With that tid bit explained, and the belief that discomfort and sicknesses will go away, and if you are assuming that what you learn on earth goes with you to the afterlife... here is my two cents...
Functioning is only a relative concept. Autistic peoples (assuming therapy is involved in their lifetime) have to learn how to function. "Normal" functioning (potty training, adaptive behaviors, social capabilities) is only needed to survive this demanding earthly existence. What is there in heaven or in spiritual dimension that they are not prepared for? They already existed. They just need to function on earth as we want them to. Neurologically speaking, the brain is exercised and probed in therapy to adapt to more normal functioning (relatively dictated on earthly terms). How many times do you hear about the neurological brain being utilized for functioning in the afterlife? Potty training and other behaviors associated with autistic behavior are not held to the same standards as a spiritual life, because they are irrelevant.