My own personal opinion is that Nintendo refuses to over-manufacture. They'd much rather have customers go wanting than end up with a vast surplus. I don't really believe in the "trying to create buzz" idea because it doesn't really make any sense. A a business you'd much rather actually sell your product than have people want your product but not be able to give you the money. If it's a by-product of under-shipping, however, then I think Nintendo would be very happy with that.
This is classic Nintendo, to be honest. In the NES era, they were accused to killing developers because they'd manufacture far less cartridges than developers requested and that title would be completely sold out by the end of the year. It's part of their business culture.
