Using the threat of "going Catholic" doesn't seem to make much sense. If your kid is such a stud then you would assume he'll be a varsity member as a sophomore, whereas the two best Catholics don't have a habit of bringing up either sophs and certainly no freshman.
I suppose you can make try it but if this works then the HS coach is not the sharpest knife in the drawer.
This policy of not taking up upperclassmen is due to the fact that they don't have to. You parents that keep sending your kids there in droves have caused this. Believe me if there were 40% less kids going out for the team, they would cherry pick the best underclassmen in order to compete. But now they would rather have a policy of not, as to not have to hear the complaining of why one sophomore was brought up and another wasn't. Has nothing to do with what's best for the program or the child. They can be fat and happy and not have to even look at players until they are upperclassmen. So to the parents who complain about this policy. If you have an underclass superstar and want them to play on varsity early, stop trying to change or merely complain about it. Vote with your feet and show us just how unbelievable little Johnny is somewhere else.