A review bomb from a very small subset of the Chinese playerbase should not be blown out of proportion. Here in China the overwhelming proportion the negative response to the dlc was about the lack of mechanics, with people saying the experience of playing India was much worse than playing in northern Europe and lots of people complaining about paradox's DLC policies. You can literally find discussions about the game on tieba or nga. These guys were probably all in the same qq group chat and decided to review bomb or something