Flilix on 24 November 2016
I doubt that Pokémon Stars is ever going to happen.
Pokémon Grey was rumored even before Black and White were released, same with Pokémon Z.
Game Freak was obviously planning to release Pokémon Grey at first (Kyurem is a grey dragon), but they changed their mind and released two games instead. This was a good idea: Black2/White2 sold more than Platinum, Emerald and Crystal (while Black/White sold less than its predecessors).
They also intended to release Pokémon Z (Zygarde), but they realised they could make more money by skipping it and just releasing remakes and new generation games instead.
In Sun and Moon, there is no 'third legendary', nor any other sings that Pokémon Stars is going to happen.
