Revolt in China!
Nonsense about there never being a revolt there. Taiping was home grown, as was Boxer and Sun. Heck, Mao's crusade was a revolt. Read your history, China has been nothing but revolts until recent times.
However, Goulash communism requires the standard of living to rise every year so that people will put up with the government. China simply cannot keep growing at the astonishing rate it has for too much longer. There will be stagnation, and people will blame the government.
This could lead to horrendous trouble. At the moment the Chinese government is fairly benign because there are no threats. But if there is a real demand for democracy, will they adopt it (probably in a Russian style) or stand firm and fight.
Either way, it is very important to keep trouble makers on a tight leash. New AI technology for monitoring communications can help a lot with this.
The real thing that the UK could learn from China is the way their bureaucracy controls and tames the internet. It is not too heavy handed, so most Chinese do not complain. Just enough where needed.