While the big NPCs of Battle for Azeroth have had plenty to do, the role of the player in the narrative is odder than ever. In the vanilla game, adventurers were faceless members of a larger army. We participated in great battles, but we were mostly there to shoot and loot. Burning Crusade and Wrath of the Lich King elevated the player, having NPCs marvel at us and thank us for our service. Later, in Legion, I became the Highlord of the Silver Hand and worked side by side with the biggest characters in Warcraft lore. I’ve run a garrison, saved the world, and I now hang out with the High King of the Alliance constantly.
In Battle for Azeroth, the developers are getting away from grand space opera theatrics and broad strokes and into grittier territory. So far, there have been some wins: Zones like Drustvar and Nazmir have been intriguing stories set in gorgeous setpieces. There have also been raging controversies, like the one around Warbringers: Sylvanas. So far, one of the biggest challenges the writers have is dealing with a world that is hard-locked into two factions.
Formerly, when you visited a new zone, you would be very careful, tiptoeing around, cause everything was higher level than you. But as you dinged (leveled up), you would get more powerful relative to the locals. So you would feel more confident and capable. Dinging came to represent more HP, more Mana, better hit ratio, more crits, more talent points. you felt REALLY good when you dinged, like you had accomplished something. Almost tangible. You would think "now I can go back and take that mob/group that ganked me". And then when you had done all the quests, you would move to another zone and do it again. Fun!