Totally disagree. She clearly has very skewed boundaries and is partly responsible for how he is coming across. He has been spoiled rotten, and needs a short sharp shock.
If he masks it's not really him. And nobody should have to be his safe person necessarily, relationships are a two way street. The current him needs therapy and time away from his mother. I'm not convinced he's autistic, just infantilised to a massive degree and constantly told he's hilarious.
Edited as autocorrect seemed to think infanticide was more appropriate than infantilised. Odd.