This wouldn't make any sense since people are already openly considering if this is China's "Chernobyl event" (for someone that doesn't know, Gorbachev for one has said that Chernobyl was a catalyst that lead to the fall of Soviet Union). That isn't just speculation in the west but on Chinese twitter too I think. So the virus has actually fomented opposition to regime. Secondly there's not much more that the regime could even do to crack down on population unless they start to actually shit like total systematic genocide of Uighurs. (A lot of the population is already in concentration camps.)