Are monks the only class that has an exp boost quest in wow?

No, monks are not the only class with an experience boost quest in World of Warcraft. While monks have a unique quest called "The Wandering Isle" that provides a significant experience boost for leveling, other classes also have similar quests tied to their respective starting zones or expansions. Additionally, various in-game events and bonuses can provide experience boosts for all classes, such as holiday events or the "Rested Experience" system.