While that may be true, I think that scale plays a role here. The ancestors of this virus were bouncing around between a relatively small set of humans and ani

While that may be true, I think that scale plays a role here. The ancestors of this virus were bouncing around between a relatively small set of humans and animals for a while before becoming SARS-CoV-2. Now with a significant portion of the world infected, it does not seem unreasonable that it would mutate. Although at that point it probably would not be considered the same virus anymore.