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.
Indeed, it only sounds like good for crypto world because of its automation and also offers faster transactions but in reality I don't think it will hype btc's price. It's point of application is only limited for walmart coin, actually they could made a wiser decision if they also accepts btc payments. But who knows? Maybe it's just their first step for utilizing even more options like crypto 
.