Nintendo hasn't confirmed Mario Kart World DLC, but most players think additional content is inevitable. One obvious source of inspiration is Donkey Kong Bananza, the company's latest first-party Switch 2 game. Reddit posters recently discovered identical names in the credits of the 3D platformer and kart racer (spoilers below).
Tsuguo Mogami voices King K. Rool while Yuu Hayashi represents Void Kong in Donkey Kong Bananza. While initially not drawing much attention, the actors also show up in the Mario Kart World credits. However, in Mario Kart World, they aren't listed with any character names.
It's possible that the actors went unnoticed as NPCs, or they played more significant roles in earlier builds. That hasn't quieted speculation that the Donkey Kong characters will become playable racers in future DLC.
Donkey Kong Bananza already has some presence on the racing circuits. Donkey Kong himself and the more mature Pauline are available as Mario Kart World characters. Even so, it's possible that the younger version of the singer could make an appearance. Multiple other contenders, like Void King, would also add diversity to the roster. Nintendo has had success with crossover characters in Mario Kart 8 Deluxe DLC and Super Smash Bros titles.
Mario Kart World caused controversy when it was announced, with the physical version costing $80. Former Nintendo marketers and current YouTubers Kit & Krysta advised against announcing any DLC. Additional paid content would only add to worries about the affordability of Switch 2 games. Nevertheless, the open-world nature of the title seems inviting to adding regions with new drivers.
With continued strong sales, Nintendo's latest racing game hasn't struggled to keep players engaged. Still, it will be surprising if the company doesn't debut fresh Mario Kart World characters and tracks in the future.