This was all over the news here in Chicago because some wrestler went from Downers North to Montini and wasn't allowed wrestle. That's likely where this issue started to take shape, because it's in the news and some lawyer wants to make a name, bla bla bla. But talking with parents of Jr High kids who are playing sports, the Catholic schools up here scope out the kids and offer them 'discounts' on tuition before this all happens.
I can understand why kids would want to go to these schools with higher graduation rates and better prep for colleges, and just overall more exposure/connections. The rules should be the same both ways in regards to transfers. Why should the kid have to sit a year one way and not the other? That doesn't make sense.