To put the headline in context, this is a necessary move to unlock funding for preparation and potential mitigation.
This is a preemptive declaration of emergency. As of today, there are no confirmed cases of coroavirus in SF.
Unfortunately that's what voters in left-leaning states with their sizable homeless and illegal population subscribed for - budget, safety, health and general "quality of life" emergencies
Discussed earlier...
https://news.ycombinator.com/item?id=22419424