Yeah, and? "A look" doesn't sound like the whole thing will be dedicated to Switch. I'm definitely expecting talk about 3DS games, especially being close to releasing the 2DS XL.
They've also done stuff like that before where they say a direct will show Switch games and then they do also show a lot of 3DS stuff.
I think the fact that they distinguish between Switch games for the Spotlight, and Switch and 3DS games for the treehouse is notable.