In declaring the statement 'false', the Facebook fact checker confirmed there is a longstanding scientific theory it is true and provided confusing would-be counter-examples of variants of viruses exhibiting treatment resistance and cross-species leaps. Omicron demonstrated that treatment resistance is really incidental to severity, and COVID already is a problem for humans -- the question clearly was not asked by a pigeon or monkey for whom cross-species leaps of a human virus could be problematic. The would be fact check was not especially illuminating.
I personally credit the prediction attributed to Luc Montagnier back in 2020 that because COVID exhibited unnatural characteristics that exacerbated the severity of illness, he predicted that over time the characteristics would evolve out of the virus and result in a more benign illness. This is a reason why it would have been useful to have a scientific debate over the lab leak theory, because the origin of the virus informs our best guess of the path it may take in the future, which has so far confirmed to this prediction.