Lucina is a clone. I imagine Sakurai was sitting at his desk saying, "Come at me, haters." Quite frankly, I'm impressed by the amount of trolling he fit in 24 hours especially considering how busy he is.
Clones seem redundant with the ability to customize movesets. The roster is pretty robust at this point and some shoe-ins like Ganondorf and Wario have yet to be announced so I'm not too disappointed in this. Still, it seemed like one of those missed opportunities. Alts allowed for an insane amount of character additions as they'd be more-literal clones that do not require any rebalancing. If that's the difference between getting Daisy and not getting Daisy, I strongly prefer the former. If we get Daisy as a rebalanced Peach, that will shut me right up.
The roster is already so large, I'm finding myself not as bummed out about clones. There's so much variety and the addition of more female characters really does make a difference. With each game, this becomes less of an issue. In Melee, it was disappointing to get Pichu and not Wario, even though I understand why that happened (the development time was roughly what, like five weeks give or take). Sakurai has included many of the major omissions, notably regarding series representation. There are a few holdouts, mostly newer IPs and even then, we might still get characters like Shulk. And if we don't, I'm still pretty pleased that Mega Man and Pac-Man made the cut first.
For comparisons' sake, Brawl had 18 newcomers (three clones). So far, U/3DS has 11 newcomers (one clone for now, Mii Fighters have 32 varieties).