As you've no doubt seen, Nintendo and Universal recently hosted an event to celebrate the breaking of ground for the Super Nintendo World Theme Park attraction. A key detail of that was the news that a Mario Kart-themed ride would be a part of the theme park, which naturally opens up some exciting possibilities.
Some further details from the event are in this game.watch.impress article (in Japanese), which shows that plenty of ideas are on the table. One of these is an idea that Switch systems could have features to interact with the park should attendees take their system along. It's merely cited as a possibility, but Shigeru Miyamoto stated that Nintendo had achieved similar concepts in the past with its 3DS Guide: Louvre app. This was notable for a few reasons - Miyamoto-san said he believes Switch will still be growing when the park opens in 2020, and it demonstrates that portable-centric features like this are being considered for future Switch updates.
Based upon translations of the article, it seems clear that Miyamoto-san was keen to emphasize that the park may also incorporate other IPs aside from Mario - he asks people to draw their own conclusions from the decision to call it Super Nintendo World with no 'Super Mario World' logos. The initial focus of the reveals is clearly on Mario, but that may not be the exclusive angle of the attraction when it's finished.
Time to start saving up for those flights...