In a sense, I think it is. There's brand new Pokemon, who replace the roles of past ones (like Gear, Gigiasu, Churine, etc), as well as having little association to the past (besides Cynthia and a few other things), but... I think it is a rebirth. Everything is all new and the world is new, it's far away from the other places, so... in that way, it is.
As a whole? No, Pokemon is and always will be the same series, even if the Pokemon don't look like "Pokemon" are meant to. Though overall, it's brand new, which is what matters. It's a rebirth, but not a complete one, if you understand me. XD;