If you have a closer look at the map art and zoom in on the league, it does bear a pretty much exact resemblance to the dojo traditional japanese thingy.
I keep looking at the League whenever I take off from Mossdeep in the demo, and it does look pretty similar. After looking at the Hoenn art, so many things we could've noticed earlier jump out at me (Mauville's redesign, the storm clouds representing the Secret Places to catch legendaries, etc.).