Why PopCap and EA doesn't add new worlds in PvZ 2?

We want new worlds, all plants, zombies, night, pool, fog, roof, zombot and minigames from PvZ 1 bring back in PvZ 2 international version? The chinese version has more content than the international version even there worlds after Modern Day i.e. Steam Ages, Renaissance Age and Heian Age? This is really unfair!