On the contrary, autistic people tend to be way too mature for their age, often visibly so. (it used to be called the "little professor syndrome")
It seems to me that's what they actually found - the genes accelerate maturation. Maybe it's just the neoteny fetish of the modern society that makes it feel like a disorder.
> autistic people tend to be way too mature for their age
Appear to be, which isn't the same as "tend to be" because many go from being perceived as "overly mature children" to being perceived as immature adults because they diverge from social norms. Traumatized children also appear to be too mature for their age, and the likelihood of being traumatized growing up as a neurodivergent child is pretty high.
Neoteny makes people immature. Self centered, childish, irresponsible, agressive. It's well known which dog breeds cause the majority of injuries - pittbulls, which are little more than overgrown puppies.
It seems to me that's what they actually found - the genes accelerate maturation. Maybe it's just the neoteny fetish of the modern society that makes it feel like a disorder.