If you don't tell or give hints about your Bitcoin to any of your family members/relatives and you die, your BTC will be lost forever as no one will have access to your wallet. What i have suggested all of my friends to solve this problem is using a pendrive to write down all the keys of their wallet and how much assets they're holding. This will help his family members to get back all other assets after his death.
the problem is the trust between the people in the family. if someone tells a wife or husband that they have a million dollars in bitcoin on a pen drive, you never know if the wife or husband won't kill you for the money or you never know if the wife or husband won't steal the pen drive containing all bitcoins and disappear. so this has been a big headache. maybe if in the future there is a bank that has the function of acting as an intermediary, for example: the bank would keep the flash drive containing the bitcoins and the owner of the flash drive would make a will indicating the beneficiary in case of his death and if he if he died the bank would notify the beneficiaries to take the pen drive