Lelystad
Perhaps the idea is to divert the point-to-point holiday charter flights and no frills business away from Schiphol so that it maintains its status as one of the five main European hubs.
In other words, following the UK system of segregating the various business models between different airports. The UK has done it by accident through supply and demand economics (the lack of available LHR slots and the consequent expense of acquiring them), the Netherlands may do it by government planning(?). Schiphol would become more like Heathrow in this respect with Lelystad taking on a Stansted or Luton role, albeit on a smaller scale.
Surprised that Schiphol is reaching saturation point already, or is this sensible forward planning for the future?