The chance of a person from Wuhan being patient zero is approximately 1 in 630, based on calculations that take into account the population size of Wuhan, the global population and the fact that coronavirus-carrying animals are found virtually all over the world.
Taking into account that there are 28 Alpha- and Beta-coronavirus species with members that affect humans, the chance of Wuhan hosting a SARS-related coronavirus outbreak is 17,640 to 1
To date no credible theory for natural zoonotic spillover has been presented.
Meanwhile, there are at least four distinct lab origin theories, including the serial passage theory (which proposes the virus was created by serial passaging through an animal host or cell culture). There’s also a variety of evidence for genetic manipulation.
A third theory is that SARS-CoV-2 is the result of vaccine development, and the fourth is the Mojiang miners passage theory, which proposes a precursor to SARS-CoV-2 sickened the miners, and once inside these patients, it mutated into SARS-CoV-2.