Well, for Ninfia it probably the same situation with Piloswine->Mamoswine and Tangela->Tangrowth, but with a new, Eevee/Eeveelution exclusive signature Gen VI move, thus explaining Ninfia's normal typing
But, it could also be based on Happiness/Pokemon Contests coming back, explaining the bows.
And, we don't know it's the only new Eeveelution... We can still hope for a Draceon!
OR! It could be the new concept for a light type Pokemon, that's what they did with Dark/Umbreon...
But we might just be like the rest of the PokeFandom; we automatically assume that GameFreak puts depth into what they're working on, rather than just spitting out new monsters for us to abuse-- I mean, Pokemon doesn't have depth. Everytime a new gen comes out, we go into frenzy predicting things that only come true about 1% of the time.