re: Is this a legit explanation of Wuhan Virus?

Scientifically, sounds like a good documentary about origins of viruses. I'm not sure anyone is outright disputing any thing you posted.
There is dispute about the "flatten the curve".
It's just seems like we (scientists, etc) are trying to mathematically determine the future of this unknown virus. I don't think it's that straightforward.
But, I also admit, I don't know for sure either way