>There is more than enough evidence now to make a strong conclusion
I would disagree, all the evidence we have right now supporting zoonosis is circumstantial. The evidence being a mapping of early cases to around the market but given the shortcomings of this early evidence it's hard to rule out sampling bias: https://www.washingtonpost.com/documents/a5102da1-9b47-4e11-...
But so far we have not found an intermediate host nor any closely related viruses in any animals yet. By contrast for the two previous spillovers SARS and MERS they not only identified an intermediate host, but they have found many closely related viruses in animals due to the fact the virus is circulating and thus branching off into many variants. Just take a look at the phylogenetic trees of MERS: https://virologyj.biomedcentral.com/articles/10.1186/s12985-... and SARS-CoV-1: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1212604/