Turns out the "bye bye" was just to the 3DS.
http://www.nintendoworldreport.com/news/49708/boxboy-x-boxgirl-releasing-april-26
Boxboy is back, and Boxgirl will be with him.
The HAL-developed puzzle platformer will make its Switch debut on April 26 and will feature a two-player local co-op mode. After completing the more than 270 stages, new stages will unlock featuring the elongated Quby.
