https://twitter.com/ArcadeGirl64/status/789468839033483264
Nintendo showed off the Nintendo Switch a few days ago and many noticed that Splatoon and Mario Kart 8 were running on it….but they were a bit ‘different’. Splatoon showed off new weapons and hair styles while Mario Kart 8 had King Boo playable (not playable at all in MK8) in addition to two-items slots (when the original only had one).
This indicates that they would be sequels, but Rogers states that they will be enhanced ports. That would make sense, considering they look similar to the Wii U versions outside of some differences. This could indicate that Smash Brothers and Mario Maker (two other enhanced ports she discussed a while back) will be joining Mario Kart 8 and Splatoon in 2017.
Emily Rogers has been correct on many Nintendo NX rumors and Nintendo rumors in general, so I feel it is okay to trust this information and share it on 3WIREL.