This market is not known to have sold bats and by all accounts it did not. Consuming bats is a southern thing not a central thing.
Your theory also doesn't along with the evidence, that the first known cases had a significant population with no known connection to the market, 27 with connection, 14 without; and that other than the market there are no other obvious connections. If it were just some hawker you'd expect a much stronger connection to the market. And over a longer period.
I had a theory around guano used for fertilizer acting as a fomite, but found some research an hour ago that suggests SARS doesn't remain viable via that route, so SARS-CoV-2 probably doesn't either.
Do we know that bats are the only (or only likely) nonhuman host? Was there a significant population of cases with a known connection to the lab?
Pangolins Malasia I think are the next closest source genetically. China imports from there as well as Africa for TCM so but the known strains from bats are still match much much better.
Your theory also doesn't along with the evidence, that the first known cases had a significant population with no known connection to the market, 27 with connection, 14 without; and that other than the market there are no other obvious connections. If it were just some hawker you'd expect a much stronger connection to the market. And over a longer period.