At that time there are a lot of discussions of living with covid. Zhang and Shanghai have been most supportive of such policies That is why you have someone in the central government to come out and refute such policies. I don't think you understand how much pressure the central government and local government are under from foreign businesses and interests and government and overseas students and workers to abandon its strict policies. Just look at how much pressure Carrie Lam were under from foreign businesses, government and her own experts to live with covid.
A former Chinese health minister Gao Qiang would not write an article to a government publication to refute someone in Shanghai if it didn't have the blessing from the top. Even Zhong Nanshan spoke out against living with covid.
Beside, you just have someone in Shanghai government recorded and leaked a tape that complaining about the central government policies. And claimed that it is the central government fault that Shanghai couldn't abandon the zero tolerance policy. That covid isn't serious and just like a cold. That Shanghai should live with the virus.
A lung infection isn't mean serious. It is saying that person has pneumonia. The outbreak in Tianjin 42% of cases have pneumonia.
42 percent of the infections are classified as general cases who have had pneumonia.