I do have a question though as all the children will be slightly younger when sitting test will this lower overall marks needed to gain entry or will age standardisation take this in to account.
If age standardization works as it's supposed to, a child should get the same standardized score sitting the test now as they would sitting it some months hence, even though if they sat it later they would, on average, get a higher raw score. So it shouldn't have an effect on the cutoff. The music audition isn't standardized though, and it might be a little lower. It's only two months earlier, though.