She might be in Midnight, if what Metzen said about the forces of the Light has any bearing. If we need a drive-by Light villain to vary us from the tentacle boys, I'd rather it be her than the Arathi Empire. Maybe she's there as a frenemy at first and turns on us, or something like that.
But I don't find her necessary per se. Blizzard is already sowing the seeds for a Light themed antagonistic force, they don't need to drop a character who was only relevant for one Allied Race scenario back in BfA. WoD Yrel has little in common with that one anyway.