Welcome to FlyerTalk. I have moved your question out of the American Airlines thread into this general thread discussing the reimbursement benefit.

There is no guarantee. The terms of the benefit specifically state that gift card purchases will not be reimbursed. The rule is poorly enforced. Most people report that their purchases are reimbursed, although some need to call customer service. Nonetheless, there is some risk with any airline.

If you intend to resell the gift cards you need to choose an airline which offers physical gift cards. You could also give them to someone as a gift.