Depends, on their level of antagonist personality traits and manipulation.
If they're mentally healthy individuals, there's a chance once they've calmed, that they can take accountability for their behaviour towards their son, your DH, with therapy then reconciliation is possible, if your DH is looking for it that is.
If they are highly narcissistic, self righteous and judgmental, there's no chance, as they won't ever allow self reflection, contrition or be willing to entertain being held accountable for their behaviour and actions.
So it's pointless, you either have to go along with their delusional world, being a puppet to it or manage them.
2 main options, you resume contact and keep it very limited. Short phone calls, short visits, tell them nothing of substance, it's called 'grey rock'.
People who stay in contact with antagonistic family personality types set their own internal boundaries (do not tell them your boundaries). They accept their family member will always behave a certain way, there's no real love their as these personality types don't really exhibit it. They want to control and dominate, they don't care about your feelings or that you've been hurt by them. So you stay in the room with them until a certain point eg. being devalued, judged, criticised, etc. Then it's 'I have an appointment I forgot, have to be off, bye!'
Or similar.
So you manage your expectations, knowing it's only a matter of time before they gaslight, devalue, manipulate, judge and criticise, so you get in and out quickly.
Lots manage these individuals accordingly, short interactions, don't ever tell them your greatest joys/achievements, etc. as they don't care about your feelings, it's just more grist for their judgmental mill.
Or continue with no contact, move forward with acceptance and grief.
(Not sure if I mentioned it already, but if you want to see a classic narcissist mother who rails against 'no contact' from a daughter, watch YT Live Abuse Free).