If that happens, or if someone died with possession of bitcoin, it is just luck if he was able to leave his private keys (mostly hard drives) so he can pass his wealth to his family. Unfortunately, I never heard of companies with services with these types of concerns. Haven’t seen any insurance company that is focused on cryptocurrency. Also, a trustee firm where we can file our last will so just in case we die, our family could claim our wealth.
I'm actually hoping that someone will establish the said service. It’s just that right now, it’s not yet very much feasible. Let’s just wait for bitcoin to be massively accepted then we will see these services being offered.
If I remember correctly exchanges already have something like that in place so if you like to keep your coins in exchanges, something I do not recommend long term, then your family members have a chance to recover your coins if you at least tell them that you are holding some bitcoin, however we must remember that we are our own bank and if you are holding your coins yourself then you are the one that needs to put those measures in place if you do not want your coins to be lost when you die.