I completed “Torment Chamber: Jaina” and have been working on my Renown 11 Campaign quests (heading to Twilight Highlands). I have managed to record the change in item level for the same World Quest while on the taxi with zero changes to my character or items in my bags. Only the location of my character is different. The screenshots were taken within a minute of each other.
World Quest: Trashin’ the Camp in Revendreth
ilvl 155 - https://imgur.com/SjUiw55
ilvl 148 - https://imgur.com/mp617bo