Ubisoft is currently in a financial call with investors and through that call talked about the Switch directly, stating they have one game for the system that hasn’t been announced as well as other “new games on Switch”. We do know they have Monopoly and Rayman Legends – Definitive Edition coming to Switch and it’s highly likely Just Dance 2018 will be as well. The new, not yet announced, game could be the heavily rumored Mario + Rabbids Kingdom Battle, a game that would likely be confirmed and revealed at E3 2017.
It’s possible they have other titles in the works for the system as well, as “new games on Switch” is fairly vague. Still, they note specifically one is a new unannounced game with one or two other titles as well. We should know what these titles are soon enough.