Considering they were effectively enslaved? Unlike the Scourge where they just have to remind us that there are still plenty of evil necromancers to take over where the Lich King left off, Demons seem like they'd love to play nice from now on. While domination magic did, necromancy doesn't directly come from The Lich King or the Jailer, while Fel Magic is repeatedly described as coming directly from Sargeras. There's chaos magic, but that's pretty different from the powers Sargeras offered his followers. And there really isn't any demon lords anywhere near that powerful on their own.
There might be a new evil threat coming from demon kind but they would need another Titan-level patron to pose any kind of threat. It seems like Demons are now characterized as "alien refugees from the twisting nether."
Demon Hunters even seem to be pulling away from their identity as demon fighters, what with it seemed like they were trying to establish Tyrande as the new Demon Hunter Paragon, what with giving her Warglaves & she, like the Illidari, were someone who made a dark pact for power & have to now find a purpose after that vow has been resolved. In terms of characterization, post-burning-legion, Warlocks are essentially the "Conjurer" class & Demon Hunters are the "Bloodhunter / Edgelord / elven van helsing" class