Well... if you can hear every convo on the planet (allegedly) you surely can detect an increase cough / sick / emergency related calls in the same area.

But then your chosen government would still have to act on that information.

True, my question is quite vain since we'll never know at what level the information got stuck. monitoring, intelligence, political .. pick any

The successful early attempts to shut down covid relied on contact tracing of international travelers. Very much in the purview of the NSA.

They even failed to keep it from literally putting a carrier out of commission.