I think this is more of a dead mans switch and not replacement for individual authority. I would not be surprised if something similar exists somewhere in the US defense system actually. I'm sure there were individuals in the Soviet Union who could fire a nuclear weapon.
It's not that it's a replacement for individual authority, it just removes the need for that individual authority. You can't rely on getting several people together to make the decision to launch a retaliatory attack in time, hence the need in the US system to invest that power in one person. Because retaliation is handled by the dead man switch you can require other uses of nuclear weapons to require consensus.
