Here is why we're not getting a new generation next year.
Volcanion.
Volcanion has not been released, or even revealed yet.
They would typically want at least 6 months to promote a new generation, showing new Pokémon within the period, starting off with new Pokémon to start the hype cycle.
Volcanion is almost guaranteed to be revealed with the movie. Probable reveal in January/February/March and the event, as always, on July 16th 2016.
Now, if they were releasing a new generation in say October, hype would start between February and April with new Pokémon. To reveal new Pokémon before all the Pokémon are available in the current generation would create a marketing nightmare and a massive amount of confusion for the general populace.
If there was to be a new generation next year, then they'd have done with Volcanion what they did with Genesect in 2012 and shift its reveal to a year early in order to distribute it early and use its movie as the springboard for something in the next generation, in that case Mega Mewtwo Y.
So let's just scrap the idea of Gen VII next year. It's not happening