I would expect so. And would also expect that their parents are clued up enough to have understood the subtleties. Not all schools will have had such schemes, of course. But I expect those parents realised that at the time, so there wouldn't be a jump in prepayment.
So I'd guess that any school which had a big jump in uptake of their prepayment scheme has one which does work (eg fees fixed for the duration, prepayment for set dates, no return of fees on student withdrawal etc). It would save everyone a lot of time and the taxpayers a lot of money if the government was also capable of drawing that rational conclusion. Unfortunately, I expect they'll waste yet more of our money grandstanding instead.
I find the numbers in the article for Brighton College a bit strange. They say £50.1 million in total prepaid fees, an increase of £4.1 million. So only 10% increase. But number of pupils covered has gone up from 86 to 819. That doesn’t make sense. Looks like a mistake in the article, and it's actually an increase from £4.1 million.