yeah i would be fine with Nintendo having Mario Kart Deluxe as the only Mario Kart on Switch, although if they do that i would like to see them continue to support it with more DLC packs.
Like you said, that could free them up for other projects like a new IP or revive an old IP or another Nintendogs (MK studio develops this IP).
April 2017-Mario Kart 8 Deluxe
June 2017-ARMS
Late 2017 thru 2018-MK8D & ARMS DLC
2019-Nintendogs
2020-F Zero or New IP
When the herd loses its way, the shepard must kill the bull that leads them astray.







