Found these on wowhead. Hope they help.
“ For those who can’t find the quest, you get it from an npc on the Broken Shore base, in front of the Mage Tower (it is marked as an orange quest on the minimap).”
AND
“ If your Broken Shore is empty and you don’t see the quest-giver, make sure you’ve completed Assault on Broken Shore from Khadgar and the quests should show up. You might need to talk to Maiev and complete Champions of Legionfall at your order hall, and your specific final class quest chain to get the final champion, before your class-specific quest-giver will show up at the Broken Shore for your class mount quest.”