I just dont see it as a loophole. It is operating as intended. Young player gets drafted, he can sign an elc with the team that drafted him or he can wait and sign with whomever. No human should be obligated to work for someone, if they do not do so of their own freewill and the player has not committed to a team until he has signed a contract with them.
Further, it is incentive for the drafting team to work effectively with the player and make wise management decisions. If it looks like it is not going to work out with the player, the team still has a (typically) tradeable asset. In this case, Minny took a 63oa and turned it into a 47oa so, at least by one measurement, they benefitted and the player benefitted by getting to the NHL sooner.