What world do you thing it is that we see Kairi and Axel in the trailers? It doesn't seem to be a world we know because we've never had a world with so match forest in kingdom hearts before aside from Tarzan maybe but I'm sure that the world we see them in the trailer is not one of the worlds we know are gona be in kingdom hearts 3 so it's probably a new world. It could be jungle book from the looks of it but i can't think of a reason for Axel and Kairi to be there.