It could, but they just didnt plan such success in pre order apparently.
Yeah, I don't buy it, they should be doing some work on it, Uncharted was a supposed to be a holiday game firstly, they sure can't be having more pre-orders than what they would meet on a holiday period, they just started some tests with the game didn't they? Some beta if I recall it right, they must have noticed something that should be polished/fixed so they need some extra couple days.
Even as it's a small delay, it's not ok to keep delaying it specially when giving fixed dates already, it was not the first delay, it was the second delay with a fixed date, that's bad planning and a bit frustating they let it happen again, when you announce a game release date make sure it'll release as planned, it should incluse some extra time to cover unexpected events.
Not a big deal, really, but not something I wanna see keep happening as well.