It trades on Hong Kong Stock Ex so not a traditional Chinese market, but technically a Chinese one nonetheless. Honestly considering how many tech stocks are traded in retirement funds today, Evergrande probably once seemed like a relatively conservative investment.
Rule of thumb is about 1/3 go to foreign investment for a typical retirement account in the US. But you're right, it should be a very small part of the average portfolio.
And most of the people that live in those countries for the record.