I agree, but would like to add I also see this feature on motor control centers.The only door interlocks I see as standard are on the Glorified Knife Switches ( such as WLI ), they do not allow entry if CLOSED and cannot be thrown when OPEN. That said one side of the switch is still energized after the switch is OPEN.
I will ask, if I remember later today.
I expect either ANSI or NEMA requires this, not the NEC.
Send me a PM as a reminder.