With all respect, that's terrible analysis. The epidemiology is really clear that the start of the US epidemics was around January. It's not impossible that there were people with the disease early, but we know with absolute certainty that this number was very, very small. Because if it weren't, we'd see it in incontrovertible evidence like the death curves, and we don't.
People who were sick in December (I mean, be real: a lot of people were sick in December!) are overwhelmingly more likely to have had the flu than a disease that even in Wuhan was at just a few thousand cases at most.