Noted, but the Sorting Hat has audience of teenagers, touchy about being left out; feeling that their House was the only one not considered worth mentioning by name would bite. Further Ravenclaw is the House least inclined to dislike Slytherin, and so the one where the propaganda war will be fought most fiercely.
Not a problem from an artisitc point of view, but the Hat does have a year to write each song, and a lot of experience with the insides of teenager's heads.