Sorry, but is there any evidence that iMessage or FaceTime has been MITMed? In China or elsewhere?
(I wonder whether it's tolerated because of Apple's small market share...)
There is no eivdence that I know of. If Apple suddenly signed every message with a third key (a Chinese gov key) how would people know? Maybe a jail broken phone could detect this.. but only if the third key was added. They could do it to specific people and no one would know until it happened. I have no proof of this, only guessing what could happen.
From the article:
'Other services provided by American technology companies are available in mainland China. The country tolerates Microsoft’s Skype service for phone calls, which does not provide end-to-end encryption and as a result is easier for governments to monitor. Beijing also allows Apple’s FaceTime service, which has end-to-end encryption but does not have a WhatsApp-like feature allowing users to exchange secret codes — letting WhatsApp users combat what are known as “man in the middle” attacks.'