Dragon Quest 11 was actually the very first game that was ever announced for Nintendo’s upcoming Switch, back when it was still known as the NX. However, since then, due to loads of vague and ambiguous wording in official statements and the like, the exact status of a Switch version for the game was unknown- especially since, when Square Enix showed the game off a few days ago, they focused only on the 3DS and PS4 versions, and not the Switch one.
Dragon Quest 11 is currently slated to launch in 2017 for Nintendo 3DS, Nintendo Switch, and PS4. No western release dates have been announced yet.
Source: Rheena.com