DY – Maybe.
Also if you really hold like this L’maase, the amount of Hotzah should be set as a minimum tuition for all male children, since when the parents pay it the RBSO will pay them back and they don’t lose out.
That being said, we see time and time again how slogans are employed, but when push comes to shove no one is willing to put it into practice (for example, HaKatan’s Zionists).
P.S. By “ha’adafah” I meant in the Mezonos sense, as in anything over the bare minimum needed to run the school.