Originally Posted by ursine1

Those particular cards routinely come in and out of stock. I suspect they're now out of stock due to people purchasing all of them, perhaps in a rush ala toilet paper. The cards should come back at some point. Probably maybe.

Southwest has nothing to do with the redemption of these gift cards, that's handled by More Rewards, a third party. (Southwest does pay More Rewards for the points it collects, and gives guidance on policies.) There are still over 100 different gift cards available for purchase with points, along with a wide range of other items, so it seems unlikely that Southwest has shut down redemptions.

That said: It does appear that Southwest has removed the "Redeem for More Rewards" link from the homepage, and has edited the information on the Rapid Rewards > How To Redeem page to specify that More Rewards is now (again) only available to Rapid Rewards Credit Cardholders. So there's been a tightening at least. Since More rewards is an advertised benefit of the credit card, it is possible that Southwest is leaving this open to cardholders only because they must, per contract with Chase.