The above is most likely correct.
Everyone is crying about Samsung here, but this is no different than the iPhone preorder fiasco every year. Supply and Demand. The Note 8 set a record, in the USA, for Note preorders. It is much more popular than expected.
Every year, Apple divides its stock among carriers. Depending on when you order, you might be able to get the same exact iPhone model faster or slower, depending on if you order from Apple, Best-Buy, Costco, Target, your carrier, etc.
Samsung is no different. The difference is that the wait, while inconvenient, hasn't even surpassed the released date yet. People often wait a month or more for their pre-ordered iPhone. We most likely have mere days.
It could be worse.