I know all these things hurt and worry you, but it's all out of your hands. Your ex can leave whatever to whom ever. Hes your Ex, he really doesn't have to tell you his wishes, I actually think he should have never told you what his wishes were. I would advise you to not tell your son any of these things.. You don't need to be in the middle of that at all. Hopefully your Ex will talk to his son about such matters.

Just focus on the relationship you have with your Son.

I'm sorry your having all this to deal with.