Odyn was right, the Aspects were a mistake, and one of the biggest flaws in the scheme of the Titans. Alextrasza was subjugated during the Second War, resulting in countless deaths. Nozdormu led to the Infinite Dragonflight. Malygos led to the Nexus War. Ysera led to the Emerald Nightmare. And Neltharion ofcourse led to Deathwing, the most powerful servant of the Old Gods and the reason of many tragedies that otherwise wouldn't have occured.
Only two of them are left, we already know Nozdormu eventually turns into Murozond and we kill him, and Alextrasza will probably become an obstacle we need to kill eventually as well.
The world of Azeroth would have been far better off without them.