We’ve found a some new icons and updated legendary quest markers coming in Dragonflight Patch 10.1: Embers of Neltharion.
Legendary Quest Markers
Shadowlands previously updated major campaign quest markers with a fancy shield to better differentiate them from normal side quests and help keep players on track during their adventures. Legendary quests have always stood out due to their bold orange color, but it seems that they will also become more distinguished.