It will all depend on how Nintendo treats Amiibos after Smash.

A good Idea would to re-release MK8 with more Nintendo Characters, they could call it "Mario Kart 8 & Nintendo All Stars" or something along the lines of "Nintendo AllStars Racing"

Same thing with Mario Party, Mario Tennis, etc...

 

I personally don't care about Amiibos at all and the current use outside of Smash is pretty lacking so far.