I'm not sure I'm following: are you saying that the current president should be believed, or the former one? Similarly, are you saying that either president has cited classified information that directly contradicts the media's reporting on COVID-19?

To my recollection, neither president has forcefully declassified any evidence that supports the more egregious claims made about COVID (that it was intentionally leaked). In the mean time, there seems to be ample & bipartisan willingness among the general public to at least entertain more benign "accidental leak" theories.