A good way to gauge if somebody is coping is to think what would happen if the situation was reversed.
Imagine if the US flew 2 mature looking 6th gen prototypes and the Chinese reaction was "we actually flew a 6th gen 5 years ago" when nobody had seen it and the project was in "deep review". Imagine the Chinese government and newspapers attempted to name the aircraft bombers to somehow belittle them, argued that China not showing its aircraft was an evidence for it going better, or wrote that the USA was weaker for flying its 6th gens.
China would be a joke and rightfully so.