Not all of the CDs are made in the US and shipped worldwide. There's factories/distribution centers around the world for specific areas, so it's more of the local Sony subsidiary/distribution center's fault.
They've been shipped, stores just aren't treating them like it's a new release and needs to be put on the shelves as soon as they get it, which would probably stem from Epic not labeling the album as a "New Release" or properly promoting it to let department stores know it's a new album.
They've been put on shelves in SOME stores today. Tesco the biggest chain brand, and probably one of the biggest CD sellers in UK and Ireland, still don't have the album This release is such a mess Avril deserves so much better, and this album deserves better