Fair deal. Edmundson's play has been hindered by back problems since the Cup Final run, but at 50% retained he doesn't take up much space on the Capitals roster and presumably will play lesser minutes; and Montreal absolutely needed to move him for the roster spot more than anything.
At the trade deadline a retention spot is usually worth a 3rd so this means that the Habs traded Eddy for a 7th.
I think he is worth more than a 7th if he is recovered from his back injury.
So this is a loss for Montreal
But I understand why they did it --- they wanted to open a spot in the line-up for Xhekaj