The short answer would be good for staters but I’d appreciate any elaboration at your convenience.
OK, I’ll try. Here goes nuthin’!
Chinese doctors with serious pneumonia cases drew lavage fluids and ran the protein sequence (sanger sequencing.)
Its a bat virus! It is also 99% like a coronavirus in pangolins. (SWISS-MODEL has an online homology-modeling server through ExPASy.org which everyone can use.)
Each host causes a mutation which does show on the subsequent sequencings so the database shows you how many mutations you are from the source. Each mutation is a variation on its immediate predecessor so you can literally draw a line or map of the spread of each iteration.
Farr’s Law governs the spread of the infection in all such pandemics. The IDEA model used today is a modern computer application of that. It is a calculus type equation that gives you a picture of what is happening and prediction of what will happen. The equation depends on a factor constant called R0 (the “R-naught”) which is related to the virology of the germ. Once you have enough data you can guess the R-naught. If you have the R0 then you can draw the rest of the curve into the future. As you get new data you make smaller and smaller corrections to the constant until you know you’ve got it.
Your instincts were correct in asking this question. The premise of the article and the comments on it throughout the thread are contradicted by the curve and by the nature of the virus itself.
If you are of a scientific mind may I suggest an article in The Lancet?
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30251-8/fulltext
I do welcome correction and please forgive my mistakes and my oversimplification.