Doing the rounds right now is a post from Valve's Steam support, when a user asked about what would happen to their Steam account when they died and it's not great news for anyone hoping to pass on your Steam account.
I advise you learn from your brother's mistake, keep a copy of them somewhere secure that your loved ones will be able to access when you're no longer around. If you desire to pass it down at least.
They can say whatever they want but I wonder what a the law of each country would say about that, which is what really decides what you can put in a will or not