As for Pokémon Go and the NES Mini helping build momentum for the NX, I don't know if they will. Ideally Nintendo would love it if people being introduced to or re-acquainted with Pokémon by Go will end up transitioning to the "real" Pokémon games on the 3DS and its successor (which might be the NX depending on what it is). But that was the dream with the Wii. All those new customers that were on board for Wii Sports and Wii Fit were supposed to "graduate" to the other deeper Nintendo games. Wii Sports fan today - Zelda fan tomorrow. But that didn't happen. They played their handful of Wii Series casual titles and then never bought anything else or transitioned to the Wii U.
The theory is that these people are merely intimidated by the appearance of how complex videogames appear and would like videogames in general if they had the right title to introduce them to gaming. That's not how it actually works. It turns out the simple design of the "beginner" game is all they really need to be content until they get bored and find something else to do. There is no interest in going from something one-dimensional like Wii Sports to something more complicated and deep like Zelda. They're all fine with sticking with the simple design and will move from one simple game to another but not "up" to anything more. So odds are a lot of the Pokémon Go players are content with Pokémon Go and they don't have any desire to move to the complexity of the proper Pokémon games. The rest of the Go players would be Pokémon fans that already own the proper games and will continue to do so.
That's an oversimplification, though, because I do know a lot of people who got into PC gaming by being exposed to WoW, The Sims, or similar. While these same people didn't necessarily "graduate" to high fidelity games (ie. graphically intense FPS games that require cutting edge hardware), they most certainly bought every expansion pack and invested gobs of time into their games. I've already been thinking about how Nintendo could possibly want to build a bridge from Pokemon Go to NX, but I maybe giving them too much credit. I think it can be done in a very popular way that gives incentive to own an NX without hurting the mobile experience. They will not get every GO player, but I'm seeing a lot of addicted players right now who don't fit the Nintendo playing stereotype, and those are the gamers Nintendo ought to go after. Nintendo has hopefully been working with Niantic regarding an NX app (something that is an expansion and not the exact same mobile app, etc). I would hope to see it day-1, free to play, etc.
Beyond that, one shouldn't expect to see an influx of millions of people buying up NX solely because of Pokemon GO. There just are a lot of people who are playing GO because someone else is playing it.