...If you were in his shoes, can you declare your crypto asset to your family? Or do you think he should have declared it to them after the extended family members must have left and even if he did, the information can still leak to the extended family and from there it can escalate to other people. What opinion do you have to give in this situation?
I believe that you should have at least one trusted family member who should know about the existence of your crypto wallets. And not just to know about their existence, but also how to use the coins on the wallet, including the Seed phrase. It must be remembered that human life is not eternal and it can end at any moment, and therefore it is necessary to take care in advance that your family members can use the money after your death.