Mario should be there day 1 or they're fucking up. It's time for a 2D Zelda too. As for a new IP, I hope it's something more significant than Arms and Wii Sports, more like Pikmin, something that feels like a true new pillar franchise. I know Wii Sports is popular and kinda continuing, but it doesn't come to mind when thinking of Nintendo franchises like Star Fox, Mario, Zelda, etc.
Mario Kart & SSB almost certainly won't be year 1, I don't remember them ever being early releases. I think since they're still releasing MK8 content it'd be unwise to anyway with how well it still sells. It'd be a great time for Donkey Kong, Star Fox, and F-Zero to return (the latter of which may not be a pipedream anymore).