Are you still playing Mario Kart 8 Deluxe on Switch? How about Mario Kart 7 on the 3DS? If you are, then you'll be pleased to know that the game has received an update after more than ten years since the last one. We have no idea what it does, because it's a Nintendo update. Hooray.
The recent Mario Kart 8 Deluxe Booster Pack DLC wave added two tracks from Mario Kart 7 to the Switch racer, but hey, maybe that's not enough for you. Maybe you still like to whip out your 3DS and get a Mario Kart 7 session going. If so, you might notice an ever-so-slightly smoother gameplay experience thanks to this newest update.
So, what does this update add? Well, therein lies the rub: we have no idea. Mario Kart 7 version 1.2 was released yesterday, according to Nintendo, and the "patch notes" (which amount to one sentence) claim that "several issues have been addressed to improve the gameplay experience".

Beneath these "patch notes", you can see that the last update for the game was released on May 15th, 2012. The update addressed three shortcuts players had been taking on the Wuhu Loop, Maka Wuhu, and Bowser Castle 1 tracks in order to get ahead of opponents unfairly. Some people are mistakenly identifying that update, which was numbered 1.1, as the new update, but that's not accurate.
It's really not clear what Nintendo is actually fixing with this new update. Perhaps there was some bizarre gameplay glitch that a streamer had discovered, allowing people to cheat in bizarre ways. Alternatively, maybe someone at Nintendo found a game-breaking exploit that could brick the game and the system altogether. Since Nintendo is about as transparent as a Thwomp with its patch notes, we may never know.
The Mario Kart franchise is moving at full speed right now. Mario Kart 8 Deluxe's DLC is still bringing course after course to the celebrated Switch racer. Not only that, but we now have a date for the US opening of Super Nintendo World, which will prominently feature a Mario Kart ride designed to give you the authentic experience of racing around a Mario Kart track.
It's fair to say the arrival of this Mario Kart 7 update is somewhat bittersweet. After all, the Nintendo 3DS eShop is closing down on March 27th, so you'll no longer be able to buy Mario Kart 7, or any other game, digitally after that date. That's also when the Wii U eShop shuts its doors, so make sure you've bought whatever you want to on Nintendo's ill-fated proto-Switch (arguably, anyway) before then.