To be clear, from the time I saw the ilevel 158 trinket in Revendreth (“Thrashin’ the Camp”, rewarding the Master Duelist’s Chit) to the time I completed the quest, I changed no gear on my character nor in my bags. No spec change, nothing. I simply flew, traveled to the quest area, and did the quest.
The piece that landed in my bags was a 148 version of the Master’s Duelist chit.
UPDATE: This appears to be related to the location from which you’re viewing the world quests. Standing at the entrance of the Seat of the Primus (Maldraxxus), I’m seeing the 158 and 151 ilevel rewards. Standing near the Bleak Redoubt flight master (Maldraxxus, those same rewards are showing as 148.
Two world quests being viewed are “Air Supremacy” and “Remedial Lessons”.
Screenshots below (to note, only the position of my DK is different–you may need to click to view the larger screenshots to see the ilevels):
Air Supremacy comparison: https://i.imgur.com/yID97oN.jpg
Remedial Lessons comparison: https://i.imgur.com/dfgpzD0.jpg
