Originally Posted by
Hyral
Well originally during the scourge civil war in Capital City, it wasn't just that Arthas was losing powers due to Illidan attacking the frozen and the undead revolted for freedom, just that he was losing power and the scourge he lost contro lof went on a frenzy and/or started following whoever was strong enough to get control of them.
If I remember correctly, the "forsaken have free will" meme started in WoW. Until that retcon they were just sylvanas' scourge, just like how the dreadlords have their own scourge and other powerful undead who could stay sane during that ordeal got their own minions too.
Now if the story had remained that way, and Sylvanas was still controlling her scourge, this piece of dialog wouldn't be confusing. But with the WoW retcons it doesn't make sense.
Just shitty lore, as is usual for Legion.