Breaking off diplomatic relations is usually a very extreme measure. In the tradition of diplomacy, it is the most serious action a country can take to express its disapproval of another besides declaring war. It might be justified but it won’t be taken because the Chinese government offends extremely easily and would retaliate in kind with trade sanctions and embargoes.
If world leaders actually had the stock to stand up to China, their next move would be to say “One more fuck up and we recognise the Republic of China on Taiwan as the legitimate government of China”.