Just discovered after watching a live stream of rxysurfchic on twitch that the sweet hunter cape isn't a random drop while playing Iron Banner matches (Was playing 2 hours at a time and crossing my fingers). There is a vendor in the tower that sells the legendary capes. You have to actually play Iron banner though and Rank up at least 1 to be able to buy a cape, but man am I glad to find out that I can get it when beta starts again. Stop one for me. Want.