From WoWHead:Tyrande talking with Genn and AnduinTyrande, conspicuously absent from the Fourth War in Patch 8.2.5, has returned with some opinions on the end of the War Campaign. Story spoilers.
As expected, Tyrande is upset by the events of the Fourth War, as Sylvanas has escaped and she still wants vengeance for Teldrassil--as well as the curious matter of Elune abandoning the Night Elves.
We also learn that the Horde is now run by a council, including Baine and Thrall, instead of a singular Warchief.
Anduin: The armistice is signed. At long last, the Fourth War is over.
Tyrande: No. Not while the Black Moon still cries out for vengeance. Not until the Horde has answered for its treachery.
Anduin: Further bloodshed will not bring back the fallen. We must renew our hope and forge a future for those who survived.
Tyrande: And when the next warchief musters an army, will hope save you if it is Stormwind that burns?
Anduin: I know it's difficult to trust, but there are signs of change within the Horde. In place of a warchief, there is now a council led by Baine, Thrall, and the others. I believe they can--
Tyrande: Your faith is naive, lion son. I will sign no treaty unless it is written in the Banshee's blood!
Anduin: Tyrande!
Genn: There is truth in her words, Anduin. Peace may be on the table today, but soon enough the Horde will sound their drums and march for war.
Genn: When that day comes, no scrap of parchment will hold them back.
Anduin: The path to peace will not be easy, and not all will choose to walk it. But this is the only way to build a better future. I believe it will work, Genn.
Tyrande talking with Shandris later on
Shandris: You spoke harshly to King Anduin, Tyrande. The kaldorei can ill afford to shun the Alliance. They have provided aid and comfort to us in these dark times.
Tyrande: The young king is foolish to trust our enemies. Harsh words should be the least of his fears.
Shandris: The Banshee Queen no longer leads the Horde. Those who do seem more inclined toward peace than war.
Tyrande: If the wolf is rabid, it matters not who rides it. Sooner or later, the beast will bare its fangs.
Shandris: You are dearest to my heart, Tyrande. I beg you, let go of the Black Moon's rage and embrace the mother's light once again. I could not bear to lose you to darkness.
Tyrande: Know this. My hunger for vengeance will not be sated so long as Sylvanas Windrunner remains free--and until I know why Elune abandoned her children.
Shandris: Tyrande! Do not say such--
Tyrande: I will tarry no longer in this city of men. Let us leave for the boughs of Nordrassil.
Tyrande: From there we will dispatch the Sentinels to every corner of Azeroth. Let no one rest until the Banshee is found!
The title is supposed to have "and more" at the end, guess it was too long
Edit: The title has been edited, since this thread mostly focuses on Tyrande and we already have another thread discussing Horde leadership specifically.