Okay, I'll admit that Hoopa Unbound pic got a chuckle out of me.
You know, speaking of on-disc content, there were also some unused tracks on-disc, namely Tournament-mode related tracks, a Mario Paint medley, a Wii Shop/Mii Channle remix, the NintendoLand medley from the 50-Facts Extravaganza, and the music from the Tomodachi Life/Find Mii stages on the 3DS. They're presumable gonna be used for the Miiverse Stage, and the new Tournament mode.
...I kinda don't get why Tournament mode is online only now, unless I misread something somewhere. I mean, admit it, as tedious as it was, pitting up to 64 CPUs in a fight to the death was incredibly fun.