My autistic daughter is 3. She holds her arms up to me and says "scratch". I gently rub her arms with my fingertips. If I stop she will hold her arms out again and says "scratch". I have never heard of "Wilbarger Protocol" before reading this article but it exactly describes what my daughter is prompting me to do.
I once asked my daughter's therapist what she would be like as an adult. They politely decline to answer that question. Now I know why.
Actually, the reason the therapist (and almost all therapists for young children) won't answer that question is because outcomes have so much variation. I'm privy to the stories of many kids with autism (because I have one, and we're networked with other families) and we hear of children losing their diagnosis (being 'mainstreamed') and others at the point of being institutionalized.
It would be unprofessional for the therapist to say anything to try and predict the outcome for your daughter at age 3, as that prediction might impact your treatment and planning. If the therapist tells you to prepare for the absolute worst, you could be less inclined to try therapies that might work wonders. If a therapist tells you she'll be fine, you might also change your tactic.
Please don't assume that the therapist is withholding bad news, as that may not be the case.
I once asked my daughter's therapist what she would be like as an adult. They politely decline to answer that question. Now I know why.