It's not unusual to see threads where someone is advised to reduce or drop contact with a friend who clearly is not a real friend, by their behaviour.
Family are usually given more leeway than friends, but if a family member is creating arguments or ill-feeling, or expecting their wishes to always come first, it makes sense to avoid or cut contact with them.
I'm not saying the person who is cut out is always the one at fault, but they often can be.
Early Days - Can't stop crying
Is funeral planning a conversation you've had with your family?
sounds like a flimsy excuse IMO but then again, if you want to go NC sometimes any excuse will do.