Microsoft has entered a ten-year agreement with Nintendo to bring Call of Duty titles to Nintendo consoles. However, game development will only start once its merger with Activision-Blizzard goes through. https://www.notebookcheck.net/Microsoft-promises-to-bring-Call-of-Duty-games-to-current-and-future-Nintendo-consoles.673130.0.html
This means, the next gen Switch is just around the corner. Dev kits are probably being finished to start off new developments.