Oddly enough, this is one requirement that I have seen complied with, here ... at least, in new construction of 'strip' commercial rentals. That is, every ORIGINAL tenant space WAS provided with a circuit that fed nothing but a single receptacle, either above the door, or on the facade.
Naturally, over time and multiple tenant improvements, doors get moved, walls added and removed, and circuits tapped into. That 'sign circuit' is almost always used to feed the reception counter.
I agree that the requirement is not new; I just find it interesting the way it has been applied: to say that signs need to be on a sign-only circuit.
