[fullmetal]

Coronaviruses are unsegmented RNA viruses, where as the flu virus is a segmented RNA virus.  Those segments in the flu virus allow for a higher mutation rate and also more substantial mutations.  

I highly doubt that any coronavirus mutations (on the order of one or few base pairs per mutation) have had a substantial effect on the covid severity.  The what-if nature of these mutation questions has about a single-digit percentage likelihood of relevance, and any non-expert speculation would seem to be a waste of time.

[fullmetal]

Coronaviruses are unsegmented RNA viruses, where as the flu virus is a segmented RNA virus.  Those segments in the flu virus allow for a higher mutation rate and also more substantial mutations.  

I highly doubt that any coronavirus mutations (on the order of one or few base pairs per mutation) have had a substantial effect on the covid severity.  The what-if nature of these mutation questions has about a single-digit percentage likelihood of relevance, and any non-expert speculation would seem to be a waste of time.