Rumour: New Version of Pokémon Sun And Moon, Pokémon Stars, Is Coming to the Nintendo Switch

It'll be separate enough from Sun and Moon to avoid detracting from them, it's being stressed, and it's not imminent either. Eurogamer's sources have stated that a targeted Summer 2017 release has been push back to later in the year. It is the core Game Freak team producing the game.

Whenever it comes, a mainline Pokémon title would certainly bode well for the new console.