Unfortunately as you said it has probably been brushed under the carpet again. I can’t tell you how many times my partner and I have had that final row. Then he has got up next morning like nothing had happened. However, in your sons heart he knows it is not your fault, he may not say it because he doesn’t want to provoke the monster. He is just desperate to keep the peace.
He also might still be in denial if he asks her to stop eventually she will.
Hopefully he won’t leave it as long as I have before he starts to make changes. I’ve got a long way to go but I already feel I have achieved so much in the last week..