Between the time that the Valkyr brought Sylvanas back from the Maw after she yeeted herself off of Ice Crown, until she denounced the Horde in BFA, we had no idea what she was up to.

It's clear in hindsight when viewing the Vol'jin's death cinematic from the beginning of Legion, that Sylvanas had known plans were being further moved into motion when she was named warchief. She waited for what seemed like hours, pondering what just happened before leaving the throne room. We couldn't understand the significance of this moment yet when we first saw it, but we now know that it was Mueh'zalla whispering to Vol'jin on his deathbed at the behest of the Jailer.

So my question is this: was Sylvanas given instructions to sit and wait patiently for a message obvious to her and then to cause as much death as possible before destroying the helm of domination and joining Zovaal in the Maw? Or was he able to communicate to her some other way, perhaps using the Valkyr as messengers?

Related question: are her Valkyr actually Mawsworn Kyrian in disguise? I'm a bit confused on this portion of the retcon