When these two world quests are both active, the neutral “A Matter of Stealth” hides the Night Fae “Gormling Piper: Crumbled Ridge” from the map. This can lead to confusion on a Night Fae player’s part as to whether they’ve already done their covenant world quest – or even if it’s available to begin with – unless they fly out to Crumbled Ridge and check their quest tracker.
I completed both world quests without issue on my Night Fae hunter alt, but I really could have done without the confusion.