This makes sense to me...
I mean, look at

people said he had no moveset potential.... but when you look at what the NES Zapper games had to offer... ducks, clay pigeons, tin cans, gunmen, and even the person shooting with the NES Zapper from the fourth wall, one could come up with a crazy unique moveset.
Or

she never fought before in the Zelda games... but from what we know of her, she is capable of light magic and she uses light arrows... and she is connected to the goddesses of the Triforce so she gets Din's Fire, Nayru's Love, and Farore's Wind even though Link was the one who used them in the game.
Or

she never did anything in Galaxy games... but she is connected to the Lumas... and the Lumas can create launch stars (Up+B) or turn into Power Stars (Final Smash)... Galaxy games used the Wiimote to shoot Star Bits (Side+B) and if you shook the Wiimote, Mario would spin to pick up coins that were around him (Down+B)... and a second player could use a Co-Star Luma to attack enemies that were far away from Mario (Neutral B) so Rosalina becomes a puppeteer style fighter.