So here's something interesting. Those three Smash kiosks that were "confirmed" to be at Nintendo's PAX booth? Not there - at least not yet. I just finished setting up at our booth, and I walked by Nintendo's on my way out. It's all Super Mario Maker and Splatoon kiosks, with a Xenoblade Chronicles X video display.
I also saw a banner advertising what games can be seen and played at Nintendo's booth, and only those three games were listed.
More than one conclusion can be drawn from this, but take it as you will!
Well it could be that they're not done setting up the booth yet.