I’m an autistic adult and also an advanced degree expert is autism. I could say a lot but I want to point out three key things:
Autism is underdiagnosed, not overdiagnosed
Engaging in pretend play has nothing to do with autism. Some autistic kids don’t, some do.
Your last little theory is actually very close to the current leading theory behind what causes autism—a lack of synaptic pruning in the brain during early development. Synaptic pruning helps create ‘highways’ between brain regions and lessens the intensity of the information input we recieve. That doesn’t happen for autistic people. Also what you describe as the specific disconnect between the brain and mouth in speech is called speech apraxia and is the main reason why there are late-talking or non-speaking autistic people.
Also, Camarata has at least one thing right, which is that ABA (which I have good reason to beleive is where the “strapping children to chairs” practice is coming from) is traumatizing and inappropriate for all children, including autistic kids of any ability level or challenges.