Welp, as a long time reader who rarely comments, please be kind. :'D ...Also long post warning, sorry!
I run a Pokémon art group based on a region we made up, and for about two-ish years I've been kinda worried that the new G7 games were going to be based on Hawaii... and while this announcement did nothing to allay my fears, I figure you guys may at least find them interesting or exciting.
I've been thinking the new region is based on Hawaii
thanks to a number of hints about the place.
The first hint was the 'Strange Souvenir' found in XY, where the icon art is clearly a Tiki, and it's clearly stated that it's not from any region that currently existed as of XY. So that points to a new region, and the Tiki itself suggesting that it's a Pacific nation. Of all the Pacific nations, New Zealand and Hawaii are really the only two 'big enough' to host a region - Being a NZer myself, I can definitely say the Strange Souvenir does not match Maori carvings, but it does match native Hawaiian style quite well.
Next point, http://www.pokebeach.com/2015/08/flowers-in-pokemons-future
WPM posted this a while back, with 'flowers' given as the cryptic clue. Many nations are known for/by flowers, so this could be a bit of a stretch, and Hawaii in particular, you always think of the Hibiscus as one of the first symbols of the place.
Third, the Sun/Moon logos - To me, the Sun looks an awful lot like a compass, and Moon, while a little more abstract, seems to be an eclipse/lens flare and reminiscent of a sextant, both tools for sea navigation. All Polynesian cultures were renowned seafarers, and navigated with the Sun/Moon and also the stars, which are present in both eng/jpn logos behind the main text.
Fourth, the concept art shown in the teaser - We have a Yellow Firetruck! With a Blastoise on the back! And I'm not gonna' lie, that's awesome! But there's not many places where firetrucks aren't red, and Hawaii is one that uses yellow trucks.
Also on the concept art, the lovely big building they showed, seems to me to look like either an aquarium or a museum with all the water Pokémon silhouettes drawn on it, but the palms trees and building style making me think of a Pokémon version of the 'Iolani Palace https://en.wikipedia.org/wiki/ʻIolani_Palace
Annnd lastly, that bird! Going on all the all previous Hawaii ideas I'm running on, I think the little guys looks like this: https://en.wikipedia.org/wiki/Red-crested_cardinal
A bird introduced to Hawaii, and apparently rather common now. He certainly fits the bill with that crest of his.
At any rate, I could be totally and wildly off track with all of this, but I hope it's something you find interesting to ponder in the meantime. :'D