It contains sugar and flavorings, which generally make it difficult to get the required amount of protein while also making a healthy meal.
Don’t feel too badly. You can go ahead and use it if you want, but the now protein is unflavored as well, so this is going to produce something much more flavorful and sweet than you would normally get with the stuff called for in the recipe.
Edit: Also just took a look at the nutrition label info. Sucralose, not sugars, so it won’t mess with your carb levels so much but some people are freaked about sucralose, YMMV.
There’s also additional nutrients in there, so check that once you add 2 scoops of that powder (60g protein, vs the 55 called for in the chow) you aren’t over-boosting something that’s in there.
Again, the unflavored whey protein is used typically because it’s just a straight protein, this makes it easier to use in the recipe, but for a trial run, this is probably fine.