[Hawkeye's-911T]

"Endemism is the ecological state of a species being unique to a defined geographic location, such as an island,
nation, country or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic
to it if they are also found elsewhere."

So in a broad sense; other defined zone or habitat type could be taken to mean the planet as a whole. Therefore
(even if it is only RNA) the coronavirus, once it spreads everywhere, could be considered endemic by definition.

I suppose it may all come down to the "connotative - denotative" thing.

Cheers
JB