Emily Rogers has released a number of Nintendo rumors in the past and this latest one covers the title of Mario Kart Switch. Many just assumed that the Switch version was just Mario Kart 8 in a ‘Complete Edition’ form or a brand new Mario Kart using the base of the Wii U game….but it seems to be a blend of both.

The Switch version of Mario Kart 8 will contain all of the previous Wii U content (tracks, characters) plus all of the Wii U DLC. This shouldn’t come as a surprise since the three minute Switch teaser showed two players racing through one of Mario Kart 8’s DLC tracks — GCN Yoshi Circuit. For those 3DS owners who skipped out on the Wii U, the Switch version of Mario Kart 8 should be a very tempting offer. But why should Wii U owners care?
According to sources close to Nintendo, the Switch version of Mario Kart 8 will feature tons of exclusive content including brand new tracks, new playable characters, and a new-and-improved battle mode. That’s right, Nintendo listened to everyone’s criticisms about Mario Kart 8’s battle mode.

The Switch version will not only have every piece of content from the original Mario Kart 8, but a sizable amount of new characters and tracks as well. Hearing that the battle mode is new & improved is great to hear as well, considering the original release’s battle mode being one of the biggest issues people had with the game at launch.
These are rumors and should be treated as such. While Emily has sources and been right in the past on her Nintendo rumors, these are not official announcements from Nintendo. Please do not take them as confimeration for Mario Kart Switch or anything.
Source: Emily Rogers WordPress Site