Why would Apple release a product that will sell like hotcakes in late December? I think it's going to be October-early November.
Why? Because in time for Xmas, they'll get a sales bump from first release, and meet demand with a first shipping...
Then time to advertise it, build up stocks, and also time for word of mouth to get round. By the time people get them into their hands, and then friends and family see them and have a play, stoking buzz and demand, Santa will be a busy boy...
You can take that to the bank. 😀