If the US was directly involved in establishing safety procedures, then yes, that would be something.
But by and large, this is a China problem.
I doubt we will never know the answer.
If Trump had any kind of material evidence, he would have used it. Team Biden would be super strategic about it, I have no idea how they would communicate the intelligence. They would be wary of the populist consequences.
In a weird way, it might be better if we never found out that was true.