Seriously, what do you think?
Someone I know has 2 x DSs at a private prep, largely financed via Daddy's banking bonus. That has gone up in smoke. My acquaintance says it'll be OK as she's SURE the school will give them some financial help because they will want to keep such 'in-house' school socialised DCs, AND by providing bursaries in this way, the school will be able to meet its 'doing good for the wider community' (or however it goes) commitment to enable it to maintain its charitable status.
Sadly I suspect she's right- it will! Privilege has always begat privilege.
I don't necessarily have a problem with the charity status thing- as long as the school IS actually providing a genuine community service! But I'd think paying for a DC from a poor home to get the sort of education available to the wealthy at this school would meet the criteria better than keeping 'one of their own' in clover.