Oh shit...   https://www.nintendo.co.jp/character/mario/collection/search.html#?g=series&v=mariokart   Mario Kart Tour is considered a mainline game and the direct sequel to MK8dx (note how the arcade titles are completely absent).   Yes, this is indeed Mario Kart 9.   This probably explains why NIntendo EPD have put out such few original titles on Switch over the past two years... They've probably pumped the majority of their EPD staff into mobile development and have likely been prioritising mobile game development over Switch