Not sure I'd want to inherit my holdings to a person that I feel could try stealing my possessions.
He may not want to, but accidentally lose them. He may get stolen. There are lots that can happen until you pass away if another person holds your private key. It's much better to just give them a signed transaction that is not yet valid instead.
they are more then likely enough to be leaving their BTC to people who understand it enough to be able to use an X of Y multisig wallet with one of the keys not being released until after death.
How does multi-sig helps the situation? I don't understand.