When we released the Legendary Armory feature on July 13, one of the top pieces of feedback we heard was for the ability to hide the visual effects of the legendary trinkets Aurora, Vision, and Coalescence.
Once the build is live tomorrow, Aurora, Vision, and Coalescence will each have a new checkbox when equipped. From the player perspective, these checkboxes will add or remove their contribution to the stack that determines which effect will be displayed on your character, or none at all, if that is your thing.
https://en-forum.guildwars2.com/topic/104393-legendary-trinket-effects-update/