What makes the lore good in your opinion?

[sheggaro]

I'll start.

I think the lore's best whenever it is character driven, when there are many characters that have a history, interact with each other etc. When they 'surprise' us with tragic losses (Tirion/Varian/Vol'Jin) and when characters change. I feel like expansions like Cataclysm were absolute garbage because Deathwing was this guy that we never got to know or understand, same with Old Gods. These stories are shallow and weak.

Legion/Scourge/Alliance&Horde is where it's at if you ask me.

I think after this one if all they got left is the Void it will be a very bad time for those of us who like good stories. Azshara may be entertaining, but that's about it. But I'm very happy with the lore right now in Legion.

[Khaza-R]

The story is best when they don't make it revolve around a single character. MoP had a good story because no one was pigeon-holed íntimo being the "main character". In fact, it was probably the most equal we saw lore distributed to date. This is unlike WotLK and Cataclysm which focused very heavily on Tirion and Thrall respectively.

That's kind of what I fear about Legion. Ultimately it's going to revolve around Illidan and his new God-mode powers

[Necroofeelya]

The story is best when they don't make it revolve around a single character. MoP had a good story because no one was pigeon-holed íntimo being the "main character". In fact, it was probably the most equal we saw lore distributed to date. This is unlike WotLK and Cataclysm which focused very heavily on Tirion and Thrall respectively.

That's kind of what I fear about Legion. Ultimately it's going to revolve around Illidan and his new God-mode powers

I ultimately fear that Legion is going to revolve around the "Player Character" since we are wielding all of this power. I will cry.

But to comment on OP. Legion does have some really rich lore and I am very happy with what they are introducing (Aside from my player character comment). However, I am also very very excited for what they will do with the old gods and void in the future. Yes you are right that they really do not touch much about it in the game itself. There is quite some lore to the old gods and the void lords however.
A void expansion would mean not only massively touching up on the old gods, but introducing more lore about the titans, the universe. It would really bring things together as a whole. Again though, they dont have a lot of info in game at all right now which leaves the window open for creating a whole new arch.