Has nothing to do with Real Madrid.
It's how the world works. These days you have large agent companies, clubs are working closer with agents both in terms of signing and selling players, everyone talks. Players are in far more contact than they used to be, whatsapp etc, as well. Clubs are happy to go along with it because it works for them, but there's always overstepping certain boundaries (Liverpool and VVD) which can land you in trouble. Ole talks to Haaland, father and son, it's nothing new, and you can be certain he's trying to use it to the clubs advantage, we'd be stupid not to. Dortmund accepts it because it usually works for both parties, if they suddenly end up in a situation where players are consistently forcing their way out of the club, then they'll start protesting. It hasn't happened often, Dembele is the last one and it landed them an obscene amount of money.