Bioshock Infinite uses Steamworks, so it doesn't matter when Amazon "releases" the game since it has to be downloaded and run via Steam. Steam release date is 25th, but maybe preloads start tomorrow. Otherwise, pretty odd for Amazon to release keys so early.
It's not false advertising. You know darn well when the game is going to be released officially. If Amazon wants to give you your download code early, they have the right to do so. It's the same thing as if you buy a game that uses the internet, and it gets delivered early. Perhaps you can install the game early, but if the game company doesn't allow access to the server, that's not the fault of the person who delivered early. Just be patient and be happy knowing you've got your game.
Actually I didn't, and it didn't say "get your download code" it flat out says "download the game March 22nd"...or it did. It flat out says "Available Now" on the page...which is even worse. Although it now says "pre-load now/play later" in the title which is different than what it was. It's deceptive for sure, and not right.
Also, never said anything about amazon not being allowed to give us download codes ahead of time, they should be more clear of what you are actually buying as before they didn't indicate it (or at least didn't indicate it clearly).
Anyways never really pre-ordered anything from Amazon before but now I guess I'll be a bit more careful after this. Not a big deal, but def would have waiting to purchase had I known more.