he was saying what would the OEM calibrate to.. for exactly the reason you mentioned.
It's true. I own a pantone color calibrator myself and it does the room lighting adjustments.
However, the the room lighting adjustment change is minimal, especially in proportion to the amount of change a calibration does.
I turn the room lighting adjustment off actually as it doesn't look accurate. I could be editing a photo one day and the next day it looks off. I turn off the room lighting and all looks well again. The purpose of room lighting adjustment should be to make colors look perceptually static regardless of the environment lighting.
This device totally fails in that regard.
However there is one objective standard that is used for calibration, and that's with aligning the wavelength of the light outputted with the corresponding programming that defines color. For example, a pure red 255 value would be 650nm.
It is my understanding that this is how colorimeters work.