Got an email from Southwest that code SAVE20NOW will work on point travel only.
States it must be between 9/15-9/17 for travel between 9/15-10/31/2020. This looks like it would be every market, but going with YMMV just in case.
SAVE20NOW Terms and Conditions:
Book a Southwest® flight on Southwest.com® and swabiz.com using your Rapid Rewards® points from September 15 through September 17, 2020 and receive 20% off when you fly between September 15 – October 31, 2020 ("Promotion Period"). Enter code SAVE20NOW in the promo code box when booking. Offer is valid for domestic and international travel. 20 percent promotion code savings valid for one-way or round trip Wanna Get Away®, Anytime, and Business Select® fares booked with Rapid Rewards points from September 15 through September 17, 2020 and flown during the Promotion Period and is applied before taxes and fees. Savings are reflected in the price when entering the multiuse code SAVE20NOW in the Promo Code box on Southwest.com and swabiz.com. This discount is only available through Southwest.com and swabiz.com.
Discount is valid on new reservations only. Discount will apply only for dates within the Promotion Period. If one direction of the trip is outside the Promotion Period and one is within the Promotion Period, only the portion of travel falling within the Promotion Period will be discounted. Changes made to the itinerary after purchase will eliminate qualifications for this promotion. The discount is only valid with the provided promotion code and is not combinable with other promotion codes or fares. All reward travel is subject to taxes, fees, and other government or airport-imposed charges of at least $5.60 per one-way trip. Applicable taxes, fees, and other government or airport-imposed charges can vary significantly based on your arrival and departure destination. The payment of any taxes, fees, and other government or airport-imposed charges is the responsibility of the Passenger and must be paid at the time reward travel is booked with a credit card, travel fund, or Southwest gift card.
When traveling on reward travel, you will receive all fare product features except for earning Rapid Rewards points. Any change in itinerary may result in an increase in points. Points bookings are subject to change until ticketed. If you cancel your reservation at least ten (10) minutes prior to the scheduled departure of your flight, any remaining unused points will be returned to your Rapid Rewards account.
Offer is not redeemable for cash, and may not be used in conjunction with other special offers, or toward the purchase of a gift card or previously-booked flight, or change to a previously-booked flight. Discount is not valid on Group Travel or Southwest Vacations®, special fares, such as infant, child, military and government fares are not eligible to be purchased with points.