What's most likely his town is the closest to the E4, so that's something. You also have to remember that in Gen 2, 3, and 4, the box legend was caught between Gyms 7 and 8, so it would make sense for you to catch Kyurem around the time you meet Drayden, who I'd assume is the 7th Gym.
Well, it is already confirmed but what do the plot about the legendary dragons have to do with the gym order? It makes sense because we're supposed to go to eastern Unova to get to the league, and his town is nearby.