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?
Everything here became a issue because your friend was still living like someone who is suffering financially, when in reality he might even be earning more than his brothers who are carrying his financial burdens on their shoulders. Imagine if he had something else doing to earn a living for the main time, who would bother about how much bitcoins he owns to his name?
This is why I always advice that anyone who intends to invest in bitcoin should have something else doing to pay his bills so he doesn't have to strain himself financially during the investment period. Your friend should deal with the situation because I sense betrayal coming from someone who didn't plan adequately before investing but chose to be a burden to others.
I won't put myself in a situation where I'll be forced to declare my assets against my will. I will only declare my assets at the right time just for inheritance purpose. I must be busy earning money somewhere while I hodl. No one would even know I own bitcoins.