Originally Posted by
Aresk
Lorewise, they still do. They just do it slower with Argus. The main thing is that Archimonde (killed in Hellfire Citadel) and Kil'jaeden (killed in orbit around Sargeras) were killed in a high fel-infused place and in the Dark Beyond respectively, so they may be truly dead. Mannoroth died in the same place as Archimonde, so that leaves a few Dreadlords and Magtheridan as the surviving known demons. With Sargeras gone and the leadership in shambles, I assume it'll be some time before that power vacuum is filled.