I think they need to be careful it doesn't become defined by the smartphone compatibility. It needs a distinct identity. Otherwise people may just think 'well I have the best/most-popular stuff - e.g. Pokemon Go - on my phone already, so I guess I don't need that NX thing'
Compatibility or even just running their smartphone games makes sense, but I'm not sure they should really make much play of coat-tailing on the likes of Pokemon Go. It shouldn't be much more than icing in the marketing proposition.