Uncertain, but certainly likely
For the entirety of its existence, Pokemon's main games have been on portable systems. Sure, some offshoots like Pokemon Snap and Pokemon Stadium were on home consoles, but this series' roots are in the likes of the Game Boy and the DS. So, where does that leave Pokemon if Nintendo's next system is a hybrid?
According to a description from GameStop, Pokemon will be playable on the Nintendo Switch. "Nintendo Switch games will include new title offerings from Mario, Splatoon, Zelda, the NBA and more! You will even be able to play Skyrim on the go, or Pokemon at home with the Nintendo Switch," the listing reads.
There's the ever-persistent chance that the description is a fluke, that some copywriter at GameStop just inserted whatever popular Nintendo franchise they could think of. But, there's a better chance that this comes to fruition.
It's likely that Nintendo plans to phase out the 3DS so it doesn't cannibalize Switch sales. If that's true, with the Switch acting as a hybrid (as both a home and portable system), it'll be the only current Nintendo hardware on the market. Given that scenario, it's not tough to imagine Nintendo developing a Pokemon game for the Switch, even if it is partially a home console. It's even more likely when you consider how well Pokemon Sun and Moon sold.
Nintendo has a big Switch event on January 12 where we could very well learn if this is true. There are usually a few years between Pokemon games, so maybe it's not time for a reveal yet. However, given how popular Pokemon is right now, maybe Nintendo has found a way to cut down on that gap in order to release what could be a system-seller shortly after the Switch's debut.