Keep in mind that Apple's iCloud services in China are not actually provided by Apple. They are provided by Cloud Big Data Industrial Development Co., Ltd., and allows Apple to, "continue to improve iCloud services in China mainland and comply with Chinese regulations". [0]
This service even has different terms of service, than the standard iCloud offering (though I haven't done a diff to see what's changed).
The effect of this is that the encryption keys for the service for Chinese users, are in the hands of a state-owned company (not Apple).
I'm a big support of Apple's approach and ethics with respect to privacy generally, however if you're in China, or a citizen of China, then it's probably safe to assume that anything on or passing through iCloud, is fully accessible to the state, without requiring Apple's involvement (e.g. via subpoena).
[0] https://support.apple.com/en-us/HT208351
This service even has different terms of service, than the standard iCloud offering (though I haven't done a diff to see what's changed).
The effect of this is that the encryption keys for the service for Chinese users, are in the hands of a state-owned company (not Apple).
I'm a big support of Apple's approach and ethics with respect to privacy generally, however if you're in China, or a citizen of China, then it's probably safe to assume that anything on or passing through iCloud, is fully accessible to the state, without requiring Apple's involvement (e.g. via subpoena).
[0] https://support.apple.com/en-us/HT208351