Poor reporting as usual. It's too early and there was no mention of birth rates in that article.
IMO it will be very spread out, probably so much so that Labour and the Guardian will declare it a victory when they just look at pupil numbers. Except when all the new shiny teachers don't appear and everyone starts asking why the financial detail will give the true picture.
Private schools are not only having to increase fees through VAT but also due to increased NI and price increases across the board. Many will have to drop 'extras' and increase class sizes this will also lead to parents questioning value leading to a gradual decline in places. Of course we should also remember that all the shiny new teachers will mean more people will want to choose state.