I know you already know this, Kirie, but for others...
I preordered on Amazon.ca and just yesterday got the same shipping estimation update most other people probably did...they say they'll ship on March 3 and that I should expect to receive my game March 7 to 9. (That even though I have 'express' shipping on it which is flat out 2 days, not 4 to 6.)
When I ordered, the Trio of Towns product page on Amazon.ca told me that as a Prime member I would get not only the discount, but also free release-day delivery (as long as you qualify).
That was cropped directly off the Trio of Towns page. So I contacted Amazon.ca and asked them if it was REALLY going to ship that late. This is the key part of the response I got from them:
Suraj of Amazon.ca Customer Service wrote:The estimated date is just an estimation from the fulfillment center. You will receive an updated notification regarding the delivery dates once the item is shipped. I can confirm that you will receive you order within a couple of days after the release date, perhaps much sooner.
To help you more, I have notified our shipping department regarding your order so that corrective actions will be made to ship your order soon.
So according to the customer service department, I'll either get my game on release day or just a day or two after, but I honestly don't know, now. However, I'll almost definitely end up buying two copies anyway, so if the game does NOT get to me on release day I will just buy it digitally and either give my hard copy to my baby sis so she can try it to see if she likes it...or I'll just keep it for my secondary copy.