I think it would be silly to release another Mario Kart. 8 Deluxe sold another 4M units in the latest report. You're just going to shoot the sales of that game in the foot. But I can't think of any other Nintendo game with tires that could take a holiday spot.
Don't get me wrong, I'd love a new Kart, who wouldn't at this point but 8 Deluxe is still selling so well.