That is true but it seems like most authoritarians invent a vague emergency to justify grabbing specific powers (e.g. Trump declaring a "border emergency"), whereas a specific emergency for a specific event has a time limit.

In particular: getting Trump to rescind his border "emergency" will be a long slow process of organizing and accumulating public pressure, whereas there will be an overwhelming amount of public pressure to end the curfew as soon as the power is restored.