I agree with your point in theory, but in this instance I think seeing as the vegetables are still clearly vegetables just with a different name, and also as it was done in schools not by marketing companies, I think this story in particular is a good idea.
I think it's more like telling kids that vegetables are a positive/cool thing rather than tricking them. To me, that's pretty much the same as telling kids, hey vegetables taste good. I think a lot of the adult trickery (hey lets put some spinach in a cupcake) helps enforce the idea that vegetables=bad and therefore they must be sneaked into food, but I think promoting vegetables as "x ray vision" or something similar is just making vegetables fun, and that's good.
But I think tricking/sneaking vegetables and fruits into kids is a bad thing, because what does that teach a child about healthy eating? What does it teach a child about what a balanced diet should be like? Nothing.