Most research into viral origins is driven by sampling and sequencing of genetic material. Even without cooperation from China there is still a record of virus samples preserved for research and also found in the environment. It is not clear that China has the ability to block the reveal of SARS-CoV2 origins. It is also not clear that a revealed origin would actually change anything about efforts to deal with COVID-19.

Furthermore, your focus on China is revealing. Other nations botched their response to COVID-19 and that is their responsibility. There is no good reason for COVID-19 to have become so deadly. The blame for the impact of COVID-19 belongs with all the developed nations that had every reason to know there would be more coronavirus outbreaks after SARS and MERS and decided instead to focus on politics or on ineffective strategies such as hosing down streets with bleach instead of responding coherently to the pandemic.