Pokemon Breeding has been a concept in pokemon since Generation II. We know the basics too it, a female and male give birth to an offspring that offspring shares the mothers species and notably some of the father moves. So what if instead of it being the same species as the mother or the father it become an entirely new species unto itself? It would be somewhat similar to Manaphy and Phione, yes Manaphy produces Phione but there is no line between the two Phione cannot evolve into Manaphy. So it would be with the new pokemon through breeding. In real life inter-species breeding some times leads to a new species entirely, so why not add that concept to the game. And to expand upon it the new species would have an evolution line of it's own, moves that even it's parents did not have, abilities it's parents didn't have and so on. Do I think it's going to happen? No, but would it bring something new to the table surely. It would definitely give something for professor Elm to do.