>Heads up, Trainers! We’re revealing a never-before-seen evolved Pokémon exclusively on our Facebook page on September 25! #PokemonXY
>a never-before-seen evolved pokemon
>implies one evolved form of a pokemon we already have
we obviously arent getting one of the final starter evos and its PROBABLY not a mega evolution so that leaves
helioptile, clauncher, skrelp, flabebe, spritzee, swirlix, bunnelby, dedenne, meowstic, furfrou or an old pokemon (and maybe talonflame and honedge if they somehow arent final stage/single-stage lines respectively)
it seems unlikely that we'd get clauncher/skrelp or spritzee/swirlix evos without the other, pikachu clones havent evolved and non-eevee cross gen evos seem unlikely with megas so meowstic, furfrou, flabebe, helioptile or bunnelby evo seems the most likely
my guess is either helioptile since it was one of the earlier ones they revealed that hasnt already gotten a revealed evo or meowstic since we know its a 2-stage line
