You don't know that. None of us do. I see the offers upthread trying to give away half the team for a good-but-not-great player who won't re-sign where he is at as just as off base.
If the Winnipeg post-trade press conference is an indication, Murray isn't interested in moving Girgs, Foligno, Risto, Zadorov or other young guys who can play a "heavy" game. Assuming Eichel, Reinhart, and Girgs stay at center, we already have a future top-3 centers. Picking up O'Reilly would give us 4, so someone presumably would move to wing (Girgs or maybe Reinhart).
Roy was Grigorenko's coach in Juniors, so it seems to make sense to move him assuming the Avs have an interest.