Allow customers to purchase this product when it's out of stock

In the above example: Even though the product is out-of-stock, you have asked Shopify to allow customers to purchase this product.
By default Wipeout app does not hide such out-of-stock products so that customers can continue to purchase them as you intended.
By default Wipeout app also does not publish such out-of-stock products because if you've kept it hidden then you don't want customers to purchase.
You can change the default behaviour of the app in the Advanced Settings section of the app.