I think part of the problem here is that the way I see it, it's an answer in search of a question.

And here is where I am going to get a ton of people yelling at me about about not your keys not your coins, but as of now I think that a lot of people who are concerned about leaving an inheritance in BTC are the same ones using custodial services like Coinbase. And for the ones that are not, 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.

-Dave