Twitter user @ captured a screenshot of the listing with the aforementioned date. It appears Amazon Canada have since changed the date back to the “December 31” placeholder — which seems rather suspicious! It’s almost as though we weren’t supposed to see that.
— Shigeru News (茂ニュース) (@ShigeruNews) September 28, 2014
Not only is this now the second time we’ve seen this date, Amazon is of course the world’s largest internet-based company, so this seems very reliable. If both sources are correct, then this would also confirm that the game will be seeing a simultaneous release in the US and Europe — which would be highly likely, given that the 3DS version is launching worldwide this week.
Do note that we still haven’t had any official word from Nintendo on the release date yet, so there’s still a possibility that this was just a coincidental error. However, I’d personally say it’s safe to bet that we’ll be smashing this November.