Following that train of thought, what changed between Italy/Beijing and Wuhan? Was it sheer luck that made the first major outbreak happen in Wuhan, and not in Milan or Beijing? Or Los Angeles for that matter, I think I heard reports of suspect pneumonia cases from the US as well?

What I was alluding to with "precursor" was that it may have been the same virus, but that some mutation in Wuhan might have made it so much easier to spread. My mind just has trouble imagining a model where a virus can lie pretty much dormant for half a year in different populations, and then surge in one place only and spread from there. That may well be a limitation of my mind, I simply don't see how that would work.