Certainly there have been cases where the parents of autistic children have been asked to leave but it’s because of behavior, outbursts, not autism.
My son is on the autistic spectrum, and I’ve seen other children and young people in church who are more noticeably autistic. They’re welcome, as are children with Downs Syndrome, muscular dystrophy, etc. Yesterday I saw a young woman with a service dog.
That was exactly my point. The reason no examples were offered is that if you look into it the reason would be that the Church asked a parent to remove a child who was disrupting the service. I would be surprised to find a single example of a family being told by a church they weren't welcome soley because their child was autistic.