This is what people miss. Furthermore, it's reasonable not to want an enemy state to have access to information relating to a country's citizens. Yes, the US has done. Yes, it was wrong. Yes, they are getting a taste of their own medicine. That's why they're worried about it. They know how badly that information can be used.

Furthermore, it is clear the Chinese government has an influence over app contents. It is easy for them to use it to shape the opinions of their userbase depending on the country.