It seemed to me that it was implied that you would get the Kanto starters close to the beginning of the game so that you could run with both a new (Kalos) starter and an old (Kanto) starter so that the game felt new and awesome but still had a feeling of nostalgia.
I think it's funny that Blastoise still shoots water out of his mouth even though he has 3 canon's after he mega evolves XD
Also, I think Mega Charizard looks epic!