If you're implying they secretly disabled iMessage encryption for the China locale: No Friggin Way. That would be discovered and publicized instantly.

Not to venture into conspiracy theory territory but the fact that they have the capability in software to modify the phone's behaviour based on which country the device was sold in is concerning enough to me. The Chinese gov. can put pressure on these large multinationals that rely on China's workforce and those companies can't do a great deal about it other than comply.