Kanto is love. Kanto is life.
Not really.Aura is different than A-G power up plus pretty sure Riolu did not use aura like abilities in the battles.He trained on screen and off screen. Riolu definitely isn't stronger than Dragonite as of now.Lucario would be.Hasn't this already happened? Like with the whole aura thing and it choosing ash just like Froakie did in XY. And then it's power exponentially rising against the Onix when it battled listening to Ash.
Plus, even just as a Riolu, it already seems strong enough to hold its own against Pikachu(Granted Pikachu is pretty inconsistent).
Wouldn't be surprised if they pull of some bs like Lucario is capable of mega evolving without the stones just because of its strong bond with Ash.
So yeah Riolu is kinda justified as of now. Ash just spends more time with Riolu than other Pokemon.