I like this, I'm into this, bring it on!!
So far the Zelda representation is all over the map, all over history, and the 3D games each having their own rep would be astounding! Well... So far we don't have anything for Twilight Princess, which is hilarious since two Smashes straight had four characters in TP style... so, I'm okay with dropping Twilight Princess for now in favor of literally every other 3D Zelda. OoT has three-ish reps with Ganondorf, Young Link, and Sheik, WW has Toon Link, and Breath of the Wild has regular Link (and sorta Sheik... but nah, I wouldn't count that). Zelda reps the 2D top-down games, LBW, LttP, Spirit Tracks. and so that leaves us with Majora's Mask and Skyward Sword that have yet to be repped in Smash bros with a playable character... soooo!
Skull Kid. Majora's Mask 3D just released prior to Sakurai's design documents for Ultimate, and likely the character roster. Which is great timing, and I know he's a popular character too and probably did great on the ballot (with MM3D releasing around the time of the ballot, fresh on the minds too). And the cool thing about Skull Kid, is that he actually has three games to borrow from. Coming from OoT, he could bring in a flute, maybe skull mask, or his other friends. From Twilight Princess, he could bring in his puppet pals... creepy thing could be used for a fun attack after the Skull Kid blows a horn full of leaves... But of course, the main rep here will most obviously be Majora's Mask, with his appearance hopefully based on it wearing said mask. And Majora then all of a sudden becomes the main player here, hopefully with some sick and sadistic attacks pulled from MM... Chief among them, Majora's Wrath as his final Smash! And heck, we still haven't seen Young Link's Final Smash, maybe he too could give us some more MM representation with that too.
As for Skyward Sword. Well, I think Skull Kid's announcement could easily be packaged with a few Echoes, one of which should be Impa, Skyward Sword style, as an Echo of Sheik. Which to me would be perfect. And then we'd have the ultimate 3D Zelda lineup in store for this game. Sorry Twilight Princess, heh.