i can't help but feel the jump from bo4 zombies to CW was very different. also doesn't help the fact that CW was running on the warzone engine and the treyarch games from bo4 to before were running on a heavily modified quake 3 engine (i swear i can't be the only one who feels both classic cod zombies and doom are similar).
also one of the OG cod zombies creators left a while ago when CW zombies came out. so CW zombies really did signify a new era of zombies. honestly i used to not be a fan of it before. but i am starting to miss the cartoonish graphics b04 and bo3 had in its zombies mode. it at least gave the game character and personality looking back. though i still prefer the atmosphere of the 360 cod zombies games.