Yes, I got it
Well, obviously DHS is trying to minimize frauds and the system will work the way you describe it.
But imagine that one buys a genuine Long 5 blade and transfers the sticker to a fake blade even without checking the code /why to check it?/, thus refunding a great portion of the investment - is it possible? Other funny scenarios - sveral fake Long 5 with fake stickers, but one and the same genuine number, one sells them as second hand, people ask him /eventually/ why it has been checked several times - "yes, I've checked it several times and its always genuine!"
I think that if you want a new product, you should buy it from a trusted seller, if you buy a second hand - pay attention to some product specifics, rather than stickers and numbers. Though its just mine personal opinion only, nothing to offense, just my way.