Shelter in place is about preventing person-to-person spread of the disease through direct contact or via intermediary such as a bench, chair or physical currency.
COVID-19 is not going to spread from the plant to your house without some kind of transmission mechanism.
Shelter in place gives time for current cases to go symptomatic & become traceable, among other benefits. Testing only effectively started last week, and is still a joke compared to what other countries with outbreaks of this level are doing.
I'm suspecting Tesla is employing sock puppets, or people with too much invested in Tesla, are overly eager to void the shelter-in-place effort for an arbitrary 10K people.
There have been successes with wholesale testing in towns in Italy but those populations are small enough to test while everyone is quarantined for a short period. Then when the quarantine ends the disease will spread anyway thanks to false negatives or new imports.