Not all "experts" on autism are good people.
Not all autism service providers are good people.
I hope this is obvious, but if you're not sure if a therapy or treatment for your autistic child (or, hell, your NT child) is appropriate, trust your instincts.
If you are trying to get help for your child and the therapists refuse to treat your child like a human being with normal, developmentally appropriate needs, speak up. If they won't accept boundaries you set, end the relationship.
Your kids are kids. Make sure they get a childhood.