What is the likelihood that a novel SARS virus happens to emerge in the same major metropolitan area that also happens to host a BSL4 lab, which happens to be in a couple try with a long history of labs leaking SARS viruses?
You have the causality the wrong way around.
The lab is there [Wuhan] because that is where the coronaviruses reservoirs are.
“Shi was surprised that the outbreak was local, she said: “I had never expected this kind of thing to happen in Wuhan, in central China.” The bat hiding places that she’d been visiting were, after all, as far away as Orlando, Florida, is from New York City. Could this new virus, she wondered, have come from her own laboratory? She checked her records and found no exact matches. “That really took a load off my mind,” she said. “I had not slept a wink for days.””
https://www.scientificamerican.com/article/how-chinas-bat-wo...