It should matter. GF did all it could to give older Pokemon necessary evolutions to keep up with the newer ones, but somes still haven't reached OU. Electivire, Magmortar, Honchkrow, Kingdra, Slowking, Froslass, Togekiss, Rhyperior, Mismagius, Hitmontop, Dusknoir, Yanmega, Lickilicky, Tangrowth, Ambipom, Gallade, Umbreon, Leafeon, Glaceon, Roserade, and Weavile are all currently not OU, thus wasting slots for better Pokemon on the national dex. Even Pikachu and Charizard, the most popular Pokemon of the series, are suffering from the low tiers, thus hindering their popularity status.