Most of what has been reported in the mainstream media is about politicians not attending the opening ceremonies and such. That is probably appropriate.

I have seen where at least on marathoner (one of the favorites) has said he will not run the race because of conditions. Too hot, too humid, and too much air pollution. Offers way too much threat to his career and health. That sort of situation will be a big black eye for China. If people compete and become ill, that will be a problem.