That's true but you can still find one of them in the 1st Dark Below story mission. I'm just hoping that they will make it a weekend event where they return just for a few days. Currently you can still acquire all of the eyes, hand and heart of Crota cards so I would be disappointed if they remove the hunted fallen but leave the Dark Below enemies in the game. I feel that others would agree with me but I'm sure most people have completed all of the cards.