They already started censoring the emoji keyboard in HK, this would be even easier to justify as it is "protecting the user".

There's no zh_US (or zh_UK, etc.), so any mainlander living overseas and still use Chinese as the preferred language on their iPhones will get their IP address sent to Tencent. There's not much difference here.

There is zh_US in Apple universe: on iOS/Mac language identifier depends on Language (zh) and Region settings (US).

So, if you set Traditional Chinese for language and United States for region (https://developer.apple.com/library/archive/documentation/Ma...), [[NSLocale currentLocale] countryCode] (which Apple compares to "CN" for this feature according to this comment https://news.ycombinator.com/item?id=21242628) will return US, and [[NSLocale currentLocale] localeIdentifier] will return zh_US.

localeIdentifier also returns some other interesting things, e.g. mine is "en_US@currency=EUR", because I customized Region formats.

Average users aren't aware of its existence. Also for a lot of mainlanders living in the US they won't prefer to set their region to US because that means imperial units instead of metrics units.

What do you mean they are not aware of it? Selecting language AND country is the first action when setting up an iPhone.

(Can't argue with the second point.)

Oh I guess I misremembered. Sorry. The last time I setup a Mac to non en_US was a lot of years ago (I never used iOS devices).