I'm curious if you could elaborate on what that meant for WoW or how that might translate to Destiny 2? Bear in mind I've never played WoW but always found it interesting.
I don't think that's a great example honestly. WoW's first 2 expansions were pretty top heavy in terms of content. BC added to new races and allowed the 2 previously faction exclusive classes to be played by both factions. BC's biggest addition was the 58-70 content.
The example I'd use is Reaper of Souls for Destiny 2. Specifically the end game.