Active yeast does not taste like nutritional yeast so you're recipe will taste different when it's complete. Active yeast has a sort of malty flavor to it while nutritional yeast has a flavor reminiscent of cheese, which is probably why it's being called for in your recipe. I often see it used in vegan dairy replacements (this is where I mostly use it, with soaked blended cashews and some apple cider vinegar for a pseudo sour cream I call nooch'n'nut), but it can also just add some extra flavor complexity to any number of dishes.
I'm not sure if there's any harm in eating active yeast, but I know it certainly won't taste very good...