But they don't tend to give up power that easily right?
Also if there is some sort revolution how would they stay in power? Either the military supports them in which their potential fate doesn't matter or they have no way to protect themselves.
So if China refuses to grant them exile they will tell the army to attack people randomly or to detonate a nuclear bomb? How many would follow this order?
Given the amount of media isolation in NK, and amount of demonstrated loyalty needed to rise to high levels of the military with authority over nuclear weapons, I wouldn't want to bet my life against everyone following orders.