So I've noticed this.... pretty much every time I go to tank.
I open the Dungeon and Raid interface, click Dungeon Finder... Oh look, tanks have a satchel to win!
Here's the problem.
If I turn off DPS (both are selected), or if I click the dungeon type, to make sure its set to Random Heroic... The Satchel reward disappears. I am no longer eligible for it.
Is this a bug, or is it just conveniently ending between the time I click Dungeon Finder, and the 5 seconds later when I click Dungeon Type?