Yes, that is correct
@cheese . On most wiis there are 2 separate 12v lines, one of which is the main 12v power in, the other is the 12v regulated line.
The power in accepts anything above a certain voltage (10.1v minimum iirc) and can boost or buck it to 12v, creating a voltage line that is regulated at 12v. This regulated 12v line is where all the other regulators are powered from.
But IIRC, there was at least one board that did not have this 12v, or at least had all its regulators powered from the voltage in line. I do not remember which revision(s) this applies to, but I know it was an earlier one, and not any of the 4 layer boards.