Miyamotoo on 27 July 2017
Switch will be only Nintendo system and hardly they will be releasing any other Zelda on 3DS, having that on mind I will say 2019., we could have easily 2D Zelda game also, Aonuma actualy said that: "2D Zelda On The Switch Is “Definitely A Possibility”.
http://www.gameinformer.com/b/features/archive/2017/02/14/a-2d-zelda-on-the-switch-is-definitely-a-possibility.aspx
