Any confirmed reservations keep to the same terms agreed so your current reservations are still with the old split fee model and can't be changed by either you or Airbnb, if that helps?
It won’t affect any of your existing bookings. This change will only apply starting September 15, so all reservations confirmed before that date will remain under the current fee structure and terms. Any new bookings made on or after September 15 will follow the updated policy as far as I understand.