I doubt it. You can transfer up to X/Y as far back as Ruby/Sapphire from the Game Boy Advance (R/S > Pearl/Diamond or HG/SS > Black/White 1&2 > X/Y) ... I mean where would you find a Mew? It's always been like this. If you want the really rare ones or the legendaries you have to get them the hard way...
It feels a bit cheap to me... I dunno. I like earning my levels. I wouldn't say it shouldn't be there, but maybe there should be a choice - like use EXP share, but you don't get as much EXP for the main fighter. It used to be held item and the rest got a fraction... and HMs need to burning in fucking hell. I mean a Scyther has fucking swords for hands and can learn a bunch of slicing moves, but can't cut a bush without cut? Geezus.
People need to get over this NINTENDO MAKE TWO POKEMONS TO STEAL YOUR $$$ stuff. The game was based on the creators love of collecting bugs and trading them... frankly I love the fact there's two versions of the game. When I was younger and more of my friends had Game Boys we'd coordinate who was getting what and setup elaborate trades... if we could get everything in one version a big part of what makes the game so much fun would be lost. I get Nintendo are a big corporation who want to make money, but has any fan of Pokemon felt like they were missing out a on that much by owning one version?
On a side not the producer of the X/Y said they would never do microtranscations as they want the whole game to be about earning what you own, plus they don't want kids getting ripped off. Add to this Iwata saying he won't fire people to help make Nintendo more profitable as it will only hurt creativity and morale and I'd say Nintendo, out of the big three, are the one I have the most respect for.