Where did it mention COVID-19?
I assume things like this get flagged because the code or some metadata related to the app references COVID-19/coronavirus and the reference is spotted during some static analysis. Things like podcast names and descriptions are only going to be available at runtime via some feed or API call.
If my assumption is correct, then surely there is no need for the code itself to mention either of these terms? Even things like categories have the option to be externally driven to get around the filters.