While airlines across the globe are adding fee waivers for changes, Southwest has always had free changes. If you need to cancel a flight you get back travel funds that you can use until 1 year from the original purchase date of the flight.
Southwest announced that they will be extending the validity of all travel funds that expired since March 1 or that will expire by May 31 until 6/30/21.
Additionally, any new travel funds that you get by May 31 will expire 6/30/21.
Southwest notes that it will take several weeks before they finish programming the new expiration date policy for travel funds.
Southwest is also offering free changes with no fare difference on flights through 4/30.
Hopefully other airlines can also figure out how to allow people to extend the validity of their tickets, so they can use them next year.