I think it’s not valid to claim that it
will be quickly used for that purpose.
However I absolutely agree that it could be used to detect non-CSAM images if Apple colludes with that use case.
My point is that this is immaterial to what is going on in China. China is already an authoritarian surveillance state. Even without this, the state has access to the iCloud photo servers in China, so who knows what they are doing, with or without Apple’s cooperation.