An epidemiological nexus is much smaller than an entire city and the details of the early cases matter. Aside from the contact-tracing, investigators were able to get positive PCR recovery of sars-cov-2 from -environmental samples- at the wet markets, indicating an incredible degree of contamination there. If the nexus were in fact WIV we'd expect a very different pattern of early cases (eg conference travel - a lot of researchers from WIV were at a Nipah conference in Singapore just before the outbreak!)

You could of course argue that the authorities just covered up any damning links, but the early outbreak was pretty chaotic and information wasn't well controlled... and in any case at that point we're not longer capable of arguing based on any evidence at all.

My point is simply that a lack of fully verified lineage analysis is completely unsurprising and not at all evidence in favor of conspiracy.

I used to engineer viruses... By natural standards the Laos samples are extremely close - the mosaicity of coronaviruses in these bats complicate matters - but likely within a decade of a common ancestor to sars-cov-2. Closer than any other sample that we know WIV were working with beforehand (again, people claim they were hiding what they were doing, except there was no reason whatsoever to do so before the pandemic).

Though "not close" for sure in the sense that even if they did have these strains, you would never evolve sars-cov-2 from them in a dish, there simply wouldn't be enough passages to do so. And that's sort of the point - the evolutionary "risk surface area" of zoonosis is many orders of magnitude larger than this nutty lab-leak idea, and we know that these coronaviruses jump all the time from close animal contacts, having caused two other epidemics in the last 20 years...