The World of Warcraft Twitter has a new post that reveals some mechanics changes coming to the random cosmetic item drops in island expeditions. The post has been further expanded on the WoW forums to inform the community that random cosmetic items will no longer be exclusively dropped by rares players defeat. Instead, these items will be a potential drop from any monster encountered / defeated during the course of an island expedition as part of an overall change to the drop system.
After our earlier tweet, we are working on a hotfix so that the Coldlight Surfrunner can drop when ANY murloc type is present on an Island Expedition. Furthermore, we're simplifying this entire system in Tides of Vengeance. More details on that soon. https://t.co/JpWmdO8NnC
— WarcraftDevs (@WarcraftDevs) November 21, 2018
In Tides of Vengeance, all players on an Expedition will have a chance to receive cosmetic rewards based on the island’s inhabitants, rather than which enemies were specifically defeated. That chance will again be higher on higher difficulties, but there will be no need to strategize around invaders. The most efficient way to receive cosmetic rewards will be whatever tactics cause you to complete the Island quickly, on the highest difficulty that you’re comfortable.
Read more at the links provided above.