Where Rabbonim, voluntary or in response to state-sponsored coercion, posken on wearing a mask in shul, we should follow out of respect for our government. They sincerely believe wearing a mask is a health measure, and even if wrong, they should be respected.
When we go on the goyim’s streets, given that their rule is that only members of politically incorrect minorities must wear masks and refrain from gathering together, we are under no obligation to follow them. The only reason to obey an anti-semitic tyrant is fear that the tyrant will try to kill you, and if we actually believe that Cuomo and DeBlasio are ready to engage in ethnic cleansing against us we should be moving elsewhere with all deliberate speed.