There isn't any tool. It's the first time I hear this and it's a good idea. Loss of bitcoins after death has always been a concern. As a solution your private key ca be emailed a person we have defined before.
And how is your wallet going to know that you are dead? came on... My ledger wallet is not going to tell to my dad that he is going to have all my bitcoins + tokens because i am dead. Ledger can not speak for itself.
Do not be so dumb, there is no way to retrieve those funds once that we are dead (only if we gave the copy of the private key to someone before dying)
But no, Satoshi said that those bitcoins who are lost, or if the owner of the wallet is dead, those bitcoins are going to be in there forever unless they are spent.
They are just like a "contribution" to all the bitcoin holders, because no one is going to move them (sell)