I contacted amazon, and the reply I received made it sound like it's possible that it will be offered. They have to be able to ensure enough stock to offer release date delivery, which I take to mean they need to receive a promise of delivery from the publisher for a date early enough to ensure the delivery on time.
Just a question though: In the order details, it still says 2-day shipping from Prime. When I hit change shipping speed, it only let me choose standard or 2-day. The estimated delivery is Oct 9th, though. So is it ok or not?
It's okay. Most of the time, if you order something far enough in advance, 2-day (and sometimes even standard) shipping gets you the product on release day. As you get close to release, you end up with an extra option for release day delivery. My best guess is that it has to do with the shipping schedule between warehouses and such, and that if they get your order far enough in advance they send it out from the original receiving warehouse rather than shipping it to another regional warehouse, from whence it ships to the customer.
Jonathan would be correct. Just pick the 2 day and they will upgrade it. I have been doing release date shipping for most of of my games through Amazon and they have always come through for me. Get it in early enough so like Jonathan said they have time to make sure you can get it same day. A lot of times I will also get the strategy guide with it even if they say it will come a different day. Not sure if I am just lucky with that, but it has happened more often than not.
If you have Prime and pick 2 day shipping, they may switch it to release date for you. Mine got switched, but I ordered awhile ago. The $15 credit helped me keep my preorder here as I almost went on Steam to get the digital copy same day and the free copy of Civ 5 :)
You should be all set then. I got an email from Amazon that stated it was switched to release date shipping, even though it still states 2 day. I don't think they offered it to everyone on this particular title for some reason. Amazon hasn't not met the date yet for me, so I'm sure we will be all set.