So it seems in 8.3 we get to see the aftermath of 8.2.5
Horde
First off it seems that as guessed the horde will not have a new warcheif…
Lor’themar: The Alliance has sent word. They have agreed to the armistice. This bitter war is finally over.
Baine: At last we can begin to heal our wounded Earth Mother… and the wounded Horde as well.
Lor’themar: One question remains. Who will serve as warchief? Perhaps, you, Thrall, would–
Thrall: No. I told Saurfang I would not lead the Horde again.
Thrall: But perhaps the question is not who will become warchief… but whether there should be one at all.
Lor’themar: Though the Horde has changed through the years–for good or ill–our people have always looked to a warchief to guide us forward.
Baine: That legacy must end. The war nearly cost us everything. There is no place for a warchief in a time of peace.
Thrall: It is true–the Horde has changed. Our ranks have grown, and new voices have stepped forth to lead.
Thrall: This is what makes us strong. All of us, building a new future–together.
also it seems finally the darkspear have a offical leader in Rokhan…
Rokhan: Since da death of Vol’jin, da Darkspear been lookin’ ta me ta guide dem.
Rokhan: I been fightin’ for dem a long, long time… but dat don’t mean I deserve ta be deir chieftain.
Baine: I felt much the same when my father died. It happened suddenly, and I feared that I was unprepared to take his place.
Baine: But I was ready, just as you are. You proved that in Zuldazar and at Stromgarde. The Darkspear have faith in you, and so do I.
Rokhan: Heh. Ya best be stoppin’ da flattery, Baine, before it be goin’ ta me head.
Rokhan: But… da Darkspear do be needin’ a leader. A voice on da council. And if it gotta be me… den it be me.
Baine: Trust your judgment, Rokhan. It has led you this far.
Rokhan: It be havin’ a lotta help. From da Darkspear, from da loa… and from da Horde.
Yay darkspear you are no longer leaderless
As for the forsaken to no suprise (and much distain to some) it seems calia will become the new forsaken queen…
Calia: Thank you for coming, Jaina. I wanted you both to know… I have decided to leave Kul Tiras.
Jaina: You’re leaving? Why?
Calia: I received a letter from Lilian Voss of the Forsaken. She asks for my help.
Calia: The Forsaken lost their queen. For many, it’s the second time they’ve been abandoned. They feel adrift. Alone.
Jaina: But Calia, none of that is your–
Calia: They are my people, Jaina. My father gave everything for Lordaeron. I wish to honor him, and to prove worthy of the name I was born with. The name Menethil.
Derek: Right, then. So when do we leave?
Calia: I cannot ask you to come with me, Derek. Kul Tiras is your home.
Derek: I am a Proudmoore, and I always will be. But I’ve changed, and it’s time to see where the tides will take me.
Jaina: I understand, though I will miss you both. Come. Mother and Tandred would never forgive me if I let you leave without a proper farewell.
Note these is more to this meeting but its a very long one so the rest os here
https://www.wowhead.com/news=295511/fate-of-the-forsaken-leadership-in-patch-8-3-broadcast-text-spoilers
As for the alliance it seems Tyrande (and Genn to a lesser extent) are very much on the to hell with peace…
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.
With Tyrande having even harsh words over Anduin’s decision…
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!
So what is everyone opinion on these developments, i for one am happy there will be no more warchief and that the darkspear are getting a offical leader and that the night elves are not just going “oh well peace is signed lets be friends” but i do think the forsaken could have been better with a new desolate council.