Based on the context of that sentence I would say Gruber meant it more in the way of "truth to materials" (http://en.wikipedia.org/wiki/Truth_to_materials) in which Apple's design is reductive and efficient to the user. No ornament beyond the materials that construct the product.
I see you do that and I wonder why on earth anyone would be so loyal to a corporation that they would be willing to drag their own credibility down to defend the credibility of a corporation which in they have no vested interest. It baffles me and makes no sense.
That aside, let's get back to what you said:
I don't think he meant truth in terms of marketing ...snip... but truth as design fundamental.
Can you elaborate on what you think this is supposed to mean, apart from being a divertion away from the fact that Apple, more than any other company currently out there, manipulates and lies to their audience and to sustain their image as "different"?
What are some examples in which Apple misrepresents customers?