This is always what I thought. If nVidia could truly release a card twice as fast as what AMD has, using the same foundry, then they would, since that would ensure far more sales and profit than selling something that "saves on costs" instead.
In fact, had nVidia done this, to a degree, would amount to price fixing, and of course, is illegal.
Of course, now that both cards are here, and we can see the physical size of each chip, we can easily tell that this is certainly NOT the case, at all, so whatever, it's all just marketing drivel.
In fact, it wouldn't really be any different than AMD talking about Steamroller.
"Man, we got this chip coming..."