Amazon also tends to ship from the warehouse closest to your address. Should all those new titles show up in a distribution center in Tennessee and *you* are in California then they'll likely ship to the customers in the TN region first and, if any are left, move stock to CA and ship from...
Amazon US does... Every archive title I purchase there is sold and shipped by Amazon.
I've never worried about getting a title on release day as I have such a huge backlog it's rare I open and watch a title within days, much less hours, of it arriving. Even a week or two "late" isn't a big...