I just personally hope that Tetra and The King are both atleast purchasable without the 3DS version like Mewtwo was in Smash. I get that's it a reward but I shouldn't have to get the game twice just because I want two characters.
Doesn't help that 3DS games are generally cheaper than Wii U games already and by the looks of it, the 3DS version already has all the DLC on it, so as someone who bought the Wii U version, I kinda feel ripped off.
...But other than that, hope that since they're still adding characters, that they'll eventually add Vaati.