As a vegetarian I'm not 100% certain I should be eating this. It includes "chicken flavoring (list of seemingly vegetarian, but not vegan ingredients)," on the back and I think it's fine so I YOLO'd it. This flavor combo made me go looking for specifically chicken in the ingredients list, and I suspect it's more British takeout inspired. Although this is for the US market and you might be right about the average American consumer.
I've definitely seen "real cheese" labels on pepperoni and other clearly has meat pizzas before, it's a stupid marketing thing. Because once one company does it, it makes you wonder if the others pizzas are also made with "real cheese", and some people actually care if it's not despite the fact that 100% of a frozen pizza is Manufactured Food Product™.