It's impossible to prove they didn't randomly mutate a virus until it reached its current state, so people who want a conspiracy theory are already falling back to that, Russell's teapot style. But there's also no reason to care if they did or not.
I would liken it to Chernobyl if they did accidentally release it. If it wasn't natural then it could have been prevented, including the 2 million dead.
Will we ever know for sure one way or the other? That seems less likely. If it is an accident, China will hide it forever. If it’s not, it will be hard to prove unless you find the intermediary host somehow.
(Which I've lived next to most of my life and never got sick, so it seems fine.)
We still talk and try to address climate change even though we can't do much to force China to change.
Also, the facts matter. If they did accidentally release it it they at least should be reprimanded by the world for it.
Movies should be written about it, don't let them forget.
Btw seen Chernobyl on Netflix? It's good.