Check out the latest stratechery post on Apple (AAPL)
Some striking quotes on how China may be different:
"The fundamental issue is this: unlike the rest of the world, in China the most important layer of the smartphone stack is not the phone’s operating system. Rather, it is WeChat"
"For all intents and purposes WeChat is your phone, and to a far greater extent in China than anywhere else, your phone is everything"
"That, by extension, means that for the day-to-day lives of Chinese there is no penalty to switching away from an iPhone."