The next expansion will deal with the resurgence of the dragons (Wrathion finally comes back) as well as dealing with the forces of Death. Elune, some sort of aspect of the Light, has become "frenemies" with Death. Naturally the kaldorei are devastated that their goddess worked towards/allowed Tel'drassil to burn
Dragons seems legit, they are kinda silent about everthing happening in the world and azerite is kinda the perfect thing to regain their loss powers, death forces is kinda obvious as this expansion is pointing at them. The Elune part i call it 100% bullshit, dont get me wrong WoW lore and writing team is so cancerous that is actually posible but why give the means and the power up to Tyrande to fight the undead if Elune is working with them/their boss, uh? its a retarded level so big even for WoW team