Presumably they specialised in coronaviruses because of the proximity to a bat population with coronaviruses, making sample gathering much easier? Are there other areas with significant coronavirus hosts? Are there other labs that specialise in coronaviruses to the same extent? The two seem linked to me, although I have no background in this area.
So we'd a priori expect coronavirus to originate in the area with coronavirus hosts, whether it was through the lab or the market...
It's been written everywhere that the horseshoe bats most likely to carry coronaviruses live in Yunnan province, more than 1000 km away. It's where the closest COVID relative was found as well.
Also while there are other species of bats near Wuhan, they are in hibernation in winter.
Is going out with butterfly nets to catch some bats a common routine activity among virologists? I'd say if not then the proximity of the research lab to where any bats can be found is not of much relevance - if needed, any bats can be obtained, but they are likely not the most definite factory for locating a major research center.
