It showed up yesterday on Amazon in the USA for a couple of hours, before the entire listing was removed from the website. It turns out that this was a mistake. It is supposed to be exclusive to the Amazon Treasure Truck promotion in the US – fans will need to sign up for text alerts to be in with a chance of getting to buy it.
After three days of exclusivity it will also be available on the Amazon USA website, no Treasure Truck alert required – that should mean November 1 is the wide launch date.
As this was intended as an event exclusive, stock is likely to disappear quickly, as the sets are not produced in th same quantities as general release LEGO sets.
Thanks to Scott for reaching out to Brick Fanatics and helping to clear this up.