The outcome of the bidding round can be found here: https://open.overheid.nl/documenten/6733d919-3a39-4416-8fc7-52a9e12d7ba7/file

VodafoneZiggo gets 3450 – 3550 MHz

T-Mobile Odido gets 3550 – 3650 MHz

KPN gets 3650 – 3750 MHz

Many antenna towers are already equipped with 3.5 GHz hardware, so 3.5 GHz 5G should be broadly available soon.

This map has some information about the 3.5 GHz capabilities of many of the towers: https://antennekaart.nl/kaart