The Parool did not make the information up. They interviewed urban geographer Cody Hochstenbach who did a PhD on the effects of gentrification on (in)equality.
https://www.telegraaf.nl/nieuws/1050583/prins-bernhard-heeft-102-huizen-in-Amsterdam
The prince owns 102 properties. If he is the one reconverting the former ING, he will perhaps also be responsible for building a new apartment building on its parking lot, much to the anger of neighbors and visitors of the Westerpark. I worked in a building attached to the ING tower so I have seen all the petitions of the neighborhood. It seems the license was given -as usual. There must be an enormous amount of corruption in this city(hall).
I remember that not so long ago (10 years?) several property developers were shot dead. But since the crisis the real estate seems less criminal than it was.