Do the designs of the pokemon scale with the realism of the world?
Will they still have the identity of a Pokemon after a redesign? What are the financial risks of de-cartoonifying Pokemon - will children see a textured, photo realistic charizard with muted colours and still get excited in the same way simple block shapes/colours and big eyes excite them? I don't think they would see them as the same character.
Pokemon is a game for children. My friends' five year old goes crazy for it. Their 2 year old loves a fat yellow mouse plushie. If you make it look real, it's not Pokemon, it's something else. There's too much money at stake to throw that away for the sake of a a small percentage of adults with autism.