This topic would be better suited for the Chase forum and thread on travel insurance.

United does not refund tickets unless they are unable to provide service due to weather, mechanical delays, etc. None of that applies here if the flight takes off which seems likely as SMF is not closed. Does not matter what fare class is long as it is not a refundable fare your are SOL. Would be curious about whether the "insurance" sold by United when you buy your ticket would cover this type of event. I never purchase it but normally this is the response you get from UA when you call for refunds due to medical issues, etc.

It is good know that Chase MP card may provide travel insurance as this would not have occurred to me seeing as the airport is open. It is a bit different than a hurricane aftermath where the airport may open but the entire area is a disaster zone (e.g. New Orleans, Houston, Puerto Rico). The smoke is not great but Sacramento is still functioning. Ditto for Reno, Lake Tahoe, etc.