This is not an extraordinary claim; it's an obvious one. Autistic sensory processing deficits make many everyday interactions traumatic, especially in childhood. It infuriates me that this isn't obvious to you and yet you posted a comment anyway.
I interpreted taurath to be saying that it is hard to untangle causality because autistic people are almost universally traumatized. Because we know autism causes trauma, it's very hard to tell if trauma causes autism. A slight variant on this is that we know that some of the symptoms of trauma and of autism are the same, and while these symptoms are often taken to be defining characteristics of the autism syndrome, it isn't at all clear that the etiology of autism causes them through any pathway causally independent of trauma. You'd need to find a lot of non-traumatized autistic people to be able to tell, and it's hard to find any.
