Seems Nintendo considers MKT as mainline. I wouldn't be surprised
I did another mock-up of the rest of the Mario Karts that were not
How to Connect Karts to Nintendo Switch - Mario Kart Live : Home
Mario Kart Live: Home Circuit Review - Vooks
Mario Kart Live: Home Circuit review
Mario Kart Live: Home Circuit review: a simple racer that can feel
Mario Kart Live Home Circuit Mario Set Nintendo Switch NEW IN HAND
Mario Kart Live: Home Circuit – Official Site
My [Mario Kart] collection is finally complete!! : r/mariokart
Switch Longplay [060] Mario Kart Live: Home Circuit (US)
Mario Kart (Video Game) - TV Tropes