I think that if they made more eevee evo's, it might be ANOTHER BUG OR OVERUSED DRAGON TYPE. Besides, if they did make some, they might be just another kind of pokemon i call "filler pokemon".
Simply a 'filler pokemon' is a pokemon the gamefreak people randomly thought of just to add more new pokemon. They also tend to have horrible stats. Ex. Farfeched, Aipom, Bibarel, you get it.
Anyway with the eevees, if they made new eevee, they might be lame- in appearence and stat wise, so will we be better off with no more eevees or what?
might i add that leafeon was already starting to get lame so if the gamemakers try to make more well.....(that and Shuckle is a filler pokemon 2 XP)