Well, I think my wife would be able to access most of my Exchange account because she knows my mobile device password. In most exchange apps, she needs to know my mobile PIN code to log in and even make withdrawals. Fortunately, I do not hold much on the exchange. I am holding some Bitcoin on a cold wallet, and the seed phrases are in my wife's hands.
So, I don't need such a feature from exchanges. I don't store my crypto there. I believe no one should hold a lot of money on exchanges. We have seen several cases where Exchanges ask for proof of source of funds, which sometimes we cannot provide. If we cannot do it, our family members won't be able to do that as well.
Exactly because people should not make those exchange as their wallet since even if they would function after death we don't know if they are still safe especially if they experience more bigger breach which especially if they lost billions from potential hackings.
Much better if we safekeep our funds to our own wallets and just let our love ones knows that we have funds left there since for sure that everything is safe and we can make sure that they can take the money out especially if there's something bad happen to us.