Has your son been for counselling maybe, quite often old hurts and dissatisfactions can surface, perhaps he has been suffering from anxiety or something similar and sought out professional help.
Does sound as tho he has recently been unburdening himself.
Am all for counselling but think it should only ever be family counselling in situations like this so other family members can have some input otherwise these kind of hurtful and out of the blue accusations can suddenly occur, leaving family members feeling confused and upset.
Also too often grown children are actively encouraged to just estrange themselves, to disconnect, because their word for everything is automatically believed when nobody else can have their say.
Imho talking things out in a family should always be encouraged.
We have been estranged from one of our daughters for many years, talking was never an option unless she was telling others how terrible we were, she also saw a counsellor and was told to cut all ties. She literally stopped seeing or talking to us and to her three other sisters. Will not go into any more detail, am not seeking anyone’s validation or judgement.
Hoping your son gets over whatever is happening with him and you get a chance to speak to him soon. Just keep trying. Is all you can do.
Interview with the economist billionaires fear: this is how we get a wealth tax
Robert Kenyon, Reform's candidate for Makerfield. Would you let him in your house?

