I think people get into a terrible muddle with their behaviour over divorce.
My xh's brothers and sisters acted as if I had never existed [married to their brother for over 30 years] I do realise that for kids you raised must be particularly hurtful.
They behaved badly. You behaved well. I had a difficult relationship with my brother for many years, and I detached and DBed him for years, and he finally came around. Do the right thing, as you do. In one way you are showing them the right way to behave. If they choose not to see it, shame on them. I am so sorry that they are ungrateful and unfeeling right now.