YASSSS! Order hall mounts are available... FINALLY!
So to open up your questline to get your snazzy new mount, you need to have gotten your 7.2 follower, as well as finished the entire Broken Shore Legionfall questline. Then an orange quest marker will pop up at Deliverance Point right after you turn in the final quest to kill 100 demons on the Broken Shore.
Do questline. Do Scenario. Gain epic mount. Or if you are a mage, a meh mount... HA!