My theory is based on traditional Chinese appetite for exotic animal-flesh aphrodisia (most commonly snake flesh) and irresponsible, poorly reasoned greed on the part of Wuhan I. V. lab staff charged with incineration of sick and dead experimentation subjects—staff who has/have since, more than likely, been “disappeared” by CCP secret police.

1) The sick/freshly dead test-subject bats were gathered up by W.I.V. staff charged with incineration of the subjects but...
2) Rather than incinerating them, that person or persons took them in a bucket out the lab back door and sold them in the “wet market” (Huanan Seafood Market), across the Yangtze River, as wild-caught bats for extra cash. (Yes, they were wild-caught, but many/most were also infected lab subjects.) Wild-caught bats are probably at a premium, and difficult to come by.
3) The irresponsible lab staff probably thought the sick/dead bats would be safely skinned and boiled to make aphrodisiac soup, thus killing any virus/bacteria harbored by the bats.
4) Unfortunately, the quest for exotic animal-flesh aphrodisia prevailed, and the thought of wild-caught bat sashimi (just as snake flesh sashimi is often consumed as an aphrodisiac) was too tempting not to actualize for extra cash.
5) The wet-market patron ate infected bat sashimi, and the pandemic began.
6) In an effort to suppress publicity re the actual source and chain of infection, CCP police have “disappeared” all related lab staff as well as involved wet-market merchant(s) along with all evidence of the actual events.
7) Top CCP authorities are well aware of the actual chain of infection but refuse to divulge the truth as publication might compromise both past and ongoing Wuhan I. V. experimentation and biological weapons development. These authorities remain highly sensitive about any accusation such as the one made above linking the pandemic to Wuhan Institute of Virology.