Never going to happen. The NHL did away with compensation for front office a few years back. Besides that, there was always a gentlemen's agreement that allowed individuals to leave for promotions (example - Benoit Allaire leaving Phoenix to come to NYR - promotion from Goalie Coach to Assistant Coach & Goalie Coach)
It's a completely necessary part of the NHL eco-system, and gives talent a chance throughout the league. And if they wanted, nothing stops the Rangers from counter-offing an obscene amount of money for a contract extension.
The Rangers have a boatload more resources than most teams, I'm not going to complain if a talented individual gets a promotion/chance.