All radars in the Netherlands have been upgraded to process the Mode-S signals and the Mode-S ID will be displayed on all radar screens.
In fact, you can expect a significant amount of hassle from ATC if your Mode-S transponder transmits a wrong ID. And yes, transits through controlled airspace are now routinely done on a squawk of 7000 instead of something specific - after ATC has validated your callsign, position and altitude with the mode-S readout.