I'm allergic to milk so can't use milk in Hungry Jack or any other pancakes so I use water instead and it works just as great to make the pancakes.
The milk that is suggested to use for hungry jack pancakes is mostly used for flavor which is supposed to make the pancakes taste better instead of using plain water.
But I think they taste just as good with water used to cook the hungry Jack Pancakes instead of milk.
Milk isn't needed for any pancakes including Hungry Jack Pancakes unless you want to add it for Flavor.