Only Sakurai and Nintendo, iirc.
Seriously though, I can see the Lloyd Mii costume coming with another NAMCO fighter, whether it be Klonoa, someone else, or a character that has nothing to do with NAMCO, perhaps becoming a fighter himself, or just the costume not returning at all, though this is the least likely of the bunch to me, since I can't see them having every other costume return besides Lloyd. So far, every SSB4 DLC Mii (Not including the few from base roster) has kicked the can, except for Lloyd. I personally just see him suffering the same fate that Monster Hunter and Geno did, but that's just me. It wouldn't bother me at all if it did happen, considering I've never played a Tales Of game in my entire life, but at the same time I would feel sympathy towards the countless Lloyd supporters who have hoped for him for years.
I hope for Klonoa, but at the same time I know he doesn't stand a dream of a chance, unless those rumoured Klonoa ENCORE re-makes come soon, but even then he still has to compete with Lloyd, literally every Tales Of protagonist, Heihachi, Agumon, Chosen Undead and others. At this point, I'd be completely satisfied with just the franchise getting revived by a re-make, and preferably more after said re-make, but hey. You take what you can get.