Update: now confirmed by NIS America:
A listing has appeared for Langrisser I and II on Amazon Germany which suggests that the remastered Nintendo Switch game will be coming to the west. The game will be published in both North America and Europe via NIS America and is listed with a 2020 release. We shall just have to wait until NIS America confirms it to get a solid release date.
The Nintendo Youtube channel released an announcement trailer for the game so it’s confirmed