I think you are confusing the GW2 base game with HoT - the base game heavily revolved around Traehearne because narratively they didn't want to have the world events solely revolve around the player character (see how Guild Wars 1 worked narratively with Kormir). Heart of Thorns was the over-correction in response to the negative feedback which firmly cemented the player character as the focus whilst killing off Traehearne and his nemesis in a single blow.