New treasure isn't new content in any way. It just gives you more ninjas to do the very same thing you did before.

As for the content, the game is slowly catching up to the source server, such a thing takes time, English version of the game is a LOT newer than chinese.

And it's completely not true that "they have all this content that can be released tomorrow" even if they were to just give it to use in Chinese without translating it, they still need to implement all of this.

Let's take another game for an example, which is Dragon Nest in this case, English servers opened around 2 - 3 years after the source server. Only last month one of the English servers caught up to Korea to be just one month behind. Overall it took 6 years to catch up.

Adding new content to the game takes time, even if you are just a publisher, because all the time that is saved by a bit less programming needed, is again wasted by the translating process.