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 see. There I was hoping it might be that battle facility from Emerald... oh well. Nice redesign though!
Also, here's what I could tell changes after you complete the nugget mission:
You get a nugget, obviously. The man implies he might give you more?
The Kecleon moves from Steven's house, and you can enter and check out his rock collection, which I think is actually real types of rock? Let's write about the Pokemon world's geography! Let's not, nerd. (I may end up doing this)
Tate and Liza tell you they expect they will battle you.
Interestingly, time seems to have passed, since the shop owner's brother has now gone to Oldale. I guess everything is ready for the adventure to begin now...