No, the rules is literally this:
"48.1 Illegal Check to the Head – A hit resulting in contact with an opponent’s head where the head was the main point of contact and such contact to the head was avoidable is not permitted."
Now there are some points to consider before they determine more of the incident.
"In determining whether contact with an opponent's head was avoidable, the circumstances of the hit including the following shall be considered:
(i) Whether the player attempted to hit squarely through the opponent’s body and the head was not "picked" as a result of poor timing, poor angle of approach, or unnecessary extension of the body upward or outward.
(ii) Whether the opponent put himself in a vulnerable position by assuming a posture that made head contact on an otherwise full body check unavoidable.
(iii) Whether the opponent materially changed the position of his body or head immediately prior to or simultaneously with the hit in a way that significantly contributed to the head contact."
So, what happened? Trouba hit the head as proven in post 122.
Did the factors play a role?
(i) No it wasn't poor timing, poor angle. It was direct approach and lets call it unnecessary extension of body upwards towards the head as that was hit first.
(ii) This is a yes and no answer. Yes in a sense that I'd say any player going up ice will do a degree be in a vulnerable position, but point of head contact is fully unavoidable here if you hit right.
(iii) He did not change the position of body or head, even going closer to the boards right before, thus no matter what the hit would basically be the same.
So, yeah. Its a purposely dirty hit. Unfortunately.