Um... why? The virus has to jump species somewhere. If the first documented case was in Shanghai, you could make the same argument.
I think what you're trying to say is that the jump had to have happened in Yunnan, because that's where that particular bat sample was found. But that's not what the data says at all. The Yunnan virus was a relative, not an ancestor. There are uncounted millions of wild coronavirus strains we don't see for every one we sequence. There is no reason at all to believe that some Wuhan-local bat, say, had a related strain that became the covid ancestor. Or some other species, etc...
Again, that's the way viruses evolve. It's the way pandemics start. It's the way pandemics have always started. Demanding that this is somehow a crazy engineered virus dropped on us by a despotic foreign government is... how pandemics start in bad movies.