I don't think anyone can honestly deny the impact Covid-19 has wreaked on the world. It is truly a world wide event, and it seems very unlikely that its spread and impact could have been prevented.
Whilst there are some conspiracy theories that suggest the Covid-19 outbreak was a man made virus that escaped or was deliberately deployed, there is as yet no hard evidence to support such contentions.
No single person, organisation** or country is likely to be identified as being guilty of creating or failing to control the virus, which points to the likelihood of it being classed as an "Act of God."
** Despite President Trump blaming the UN's WHO
The Act of God or Force Majeure, clauses are difficult becasue there is no definitive list of such events, There will always be room for discussion about the definition, and of course its likely the insurance companies definitions will be biased towards reducing payouts, and policy holders about increasing payouts.
I suspect in due course we will see several legal challenges to insurers if they invoke AoG or FM clauses.