Where do you see anything getting swepped under the rug?
Also wasn't it quite clear that Sylvannas... just didn't care about the evil shit she was doing becuase it served her well. Obvicously she was okay with that becuase of her shattered soul. Now the jailor gave it back to her.
I do not think the other leaders will just let bygons be bygons espacially Tyrande and Malfurion.
They will definetly use her knowledge. Everything else would be stupid.
But yes i agree that Blizz tendencies to keep mysteries gets really annoying. Never answers only more questuions