Hi. For years the community has been discussing the whispers of Il’gynoth and now it is my turn to speculate.
Watching the latest Alleria animation, we may notice the narrative directly tells the viewer Alleria had to make great personal sacrifices at three key points in her life. The first being leaving her home and family behind to their fates in order to fight a greater evil. The second, she left her newborn son behind to continue this crusade and last, but not least, she gave up on a stable relationship with her partner to embrace the shadow and keep on fighting.
While reflecting on these memories, she also dissassembles her transmog and gets a new look, as if shedding skin, or rather leaving her old self behind as well.
One could say that at each of these junctures in her past where she made those choices, leaving loved ones behind, a little bit of herself died, or stayed behind as well.
That being said, we have the famous whisper: “At the hour of her third death, she ushers in our coming”.
Given that Alleria’s third death in this interpretation is when she literally embraced the void and became a shadow user, even if not immediately controlled by the darkness, one can’t help but get suspicious.
My hypothesis is that Alleria embracing the void spells the beginning to the end. She became an unwilling pawn of the void lords and Xal’atath will break her either in TWW or Midnight, probably by killing Arator, and she will either go mad or simply turn into a vessel/portal to materialize a void lord in Azeroth.
Then Xal will smirk and say this was her plan all along (I wonder if she is actually the jailer in a purple wig this entire time). Jokes aside, my point is I think Alleria is the one this particular whisper is referencing to.