There's a dual screen mention or two in the recent FW updates for the Switch. We might just be getting something like this!
More importantly, this would mean DS/3DS games are a real possibility. If the device also had a 3DS card slot on the dongle, that would be the biggest event in recent gaming for me :D Sounds outrageous, I know. As a YouTuber, though, there aren't good official options to capture 3DS software. Just look up how much and how scarce capture mods for that system are. Nintendo missed out on an untapped market with the Wii U, and this could remedy that.
Retro Tech Select - My Youtube channel. Covers throwback consumer electronics with a focus on "vid'ya games."