I think they probably "forecasted" X number of boxes. In today's world, you don't take on that much inventory until you need it, same way with your supplier. Inventory sitting on shelves, waiting to get used, is a major NO-NO for any business.
Look at Dell's model. They have raw material entering one end of their production facility, and that same material is built, packed, and loaded on a truck as finished product in about 6hrs.
There may have been a spike in demand that wasn't properly forecasted, but I'm sure they'll catch up and be on track quickly.
If they DID experience a bigger spike than they anticipated, I'd say that's a GOOD thing
Lob