On top of an excellent structure that kept players logging in to follow WoTLK Gold the story, Secrets of Azeroth permanently altered WoW's world and has fantastic rewards that incentivize the participation of players who aren't invested in lore. These items included the Titan Key weapon transmog, the Sherlock Holmes-esque Deerstalker Hat transmog, and the Pattie the Alpaca mount, among other rewards.

These rewards are still available, like the quest line, meaning that on top of having an engaging multi-week event, players who missed it are simply getting more content. The evergreen nature of the event means it provides permanent value for the player base.

World of Warcraft's developers have alluded to wanting to do more content like Secrets of Azeroth. While this would be a strong move in and of itself, simply copying the event again wouldn't really have the same impact. Secrets of Azeroth worked because it was unique and had something for every type of fan.

The story was engaging, there were some lore changes for the world, and there were plenty of cool cosmetics to unlock. While another crime caper might not have the same impact, rolling out a story slowly over weeks landed well with fans, and provided the same effort was put into rewards and storytelling again, the format could prove strong for WoW's developers to utilize again.