Walmart coin is similar to Libra coin which facebook have. The Walmart coin will not have much impact on cryptocurrency market since walmart coin can only be used to purchase things on wilmart. One of its primary purpose is to make online shopping more convenient to shoppers and while using walmart coin a loyalty award in form of coins will enter into their wallet.
just like reward points. just instead of reward points, that would be for initial purchase. rest the functioning will remain the same.