If you haven't played the most recent Zelda game on the 3DS, you're doing it wrong. It's excellent. While A Link Between Worlds might be a bit too recent to warrant, say, a stage in the new Smash, some music is certainly within the realm of possibility. And few tracks are better suited for Smash than its final dungeon theme: Lorule Castle. With its agitated mood, steadily growing texture, and brief quotations of the Hyrule Castle and Ganon's themes, this tune helped solidify Lorule Castle as one of Zelda's most memorable levels.
EDIT: We've gotten some comments about "recent" games being represented (with Pokemon X&Y and MGS4 as examples); we should have been more clear; Zelda already has two stages on the 3DS, so a third from this very recent game might not be likely. But we don't think it's impossible! We'd be ecstatic to see ALBW get some love, and we even did a Stage Select on Lorule Castle recently.