Mario Kart 8 was a hit on Wii U, but the console's small audience limited the game's sales potential. Because of this, Nintendo re-released the game with improved graphics and extra content (plus all DLC included) under the name Mario Kart 8 Deluxe on Nintendo Switch. Deluxe is the biggest (and arguably best) Mario Kart entry yet, but Nintendo's not done yet.
Nintendo just released a video of software development head Shinya Takahashi answering questions from fans. After talking about the recent addition of Nintendo Labo handlebar compatibility for Mario Kart 8 Deluxe, Takahashi stated "There will be further updates for Mario Kart 8 Deluxe, so please look forward to it." No additional details are available at this time.
Could we see more courses and playable characters added to Mario Kart 8 Deluxe in the future? Perhaps more multiplayer modes will be added around the time Nintendo Switch Online goes live in September. For now, all we can do is wait and see.