From a programmer's perspective, it isn't impossible to connect this game to the one's after gen 5. Look at what they did importing gen 5, when you get into a battle in Hoenn or Kanto, the battle mechanics are called from Pokemon Black as an overlay on screen instead of what they used before. I don't see why they wouldn't be able to do that for the new regions after gen 6. It'd take a while but I don't believe it's impossible.