As we know Sylvanas is probably the most controversial character in WoW or even Blizzard history. From the very beginning she was one of the most iconic characters, but delving deeper into her lore, too often she chose questionable decisions. Necromancy, creating a new plague, experimental camps, slavery, mind control, were tolerated in her ranks. All of this before Afrasiabi situaion. Still, this dude is just… 
Of course her greatest crimes were Gilneas, Teldrassil and bombing/betraying her own people. (I know that some love her brutal side, but no matter how you look at it, from the perspective of story this is evil) Especially in BFA and SL, this character gained more haters than any other npc.
- Many Human players hate her for turning Anduin and Uther into her private therapist.
- Many Night Elves hate her for Teldrassil and the War of Thorns.
- Many Worgen players hate her for invading Gilneas.
- Some Orc players hate her for killing Saurfang and attempting to murder Thrall.
- Some Troll players didn’t like how Vol’jin was unceremoniously killed to give Sylvanas Warchief title .
- Arthas fans hate how they made him a fart on the end of his story. I heard complaints about Jaina not saying a word at the time of her beloved true death to give room for Sylvanas monologue.
- Several Blood Elf players didn’t like how in Wrath she forced a few remianing BEs into a suicide war with the Lich King
- A lot of Forsaken players began to hate her for betraying them.
Most of the Horde players complain that they got a sticker saying “I participated in genocide” because of Sylvanas. When Alliance players are annoyed being constantly outsmarted by her in her ,4D chess masterplan" 
Every piece of content she receives turns some people against her. In general, people are tired of her.
If you still love this character, you have to understand, when she return, that Windrunner will be a complete stranger to you.
Sylvanas will not come back as you remember. She won’t be that proud, sassy and confident powerful archer. There will be no sarcasm or sharp language in her voice. When she returns, we will find her penitent and sorry for her sins, without any power or meaning. We’ve already seen how she obeys Tyrande every order without a word of objection, and there will be more of them. This isn’t the same character we saw in Cata or Wrath who, hearing the lack of respect for her person or Forsaken, could threaten you with death or deliver it to you directly. The most important thing for her was freedom. She did what she wanted, regardless of what others said. Now Sylvanas is at Tyrande call. Her whole dark ranger aesthetic was gone.
Did she even want anything to do with the Horde at all? A part of the dark ranger soul never cared about Forsaken and used Horde as a shield against anyone who wanted to kill her. The other half remembers troll, orcs and the undead in Horde as a deadly threat to her home even when Quel’thalas join them. She also doesn’t have much in common with the Alliance. Although former Alliance, Silver Covenant, VE and her family are there.
And here comes biggest problem.
Give back her prideful character. 
People will be furious arguing that penance in hell didn’t change anything. Burning of Teldrasill brought her no consequence other than becoming a neutral character.
The other group will get angry seeing her soft side. 
Saing that the real Sylvanas would never humble herself to anyone and fight for her pride and freedom until the last drop of blood.
Either way, people will get upset no matter which route Blizzard chooses. If you have any ideas to please both groups, please let me know. I thought about it for a long time and nothing comes to my mind. 
Another problem. What about other part of her soul? Uther help Ranger General but completly ignored Banshee. She still exsist, we haven’t see it being destroyed and doesn’t seem to have any regrests about what she did. Shouldn’t we be more worried that the bad part still exists?
Many believe she’s gonna return in Midnight to defend her homeland, but there are many problems with this. The defense, tactics, structure and fortifications of Quel’thalas have changed since her time in command, Sylvanas knowledge will be obsolete. She still has his banshee power? And the most important, would Blood Elves even want her back? She was a great hero in the past. But she betrayed them twice, first time in Wrath where she forced them to fight to death, second betrayed them for the jailer.
And the argument - I can’t imagine the BE expansion without Sylvanas. - doesn’t work here. Remember, in Guardian of the Dream writers completely ignored Malfurion ( 
The emerald dream poster boy ) so anything is possible for Blizzard. 
We have so many amazing characters with so much storytelling potential in Midnight. Lor’themar, Liandrin, Thalyssra, Oculeth, Salandria, Rommant, Elisande, Veressa, Alleria, Arator, Giramar, Galadin, Aethas, Halduron, we will definitely see Elisande, Velen, Umbirc, Tharll, the rest of the Horde, Aspects, and Amani trolls there. ( And of course new characters.) There are just too many of them to squeeze Sylvanas between and even if that happens I’m sure she’ll take big chunk of the spotlight.
Blizzard is unhealthy obsessed with this character, if they bring her back, I don’t believe that any writers woundn’t want write about her, which I’m sure end up stealing screentime from other Blood elves characters who’s really deserve that.
Warning!
I’m going to sound really, really controversial here, but… Let’s give her a well-deserved ending. Yes, THE ending! 
Isn’t it better to leave her in SL? Let her finally find peace next to Nathanos, together they create a new place in Maw for abandoned and rejects from all over the cosmos, or become one of the Venthyr in Revendreth. Leave her as a cool Easter Egg. But don’t return her to Azeroth. Everyone except Loyalists and Anduin wants her dead. Her story has been written many, I mean many times. Nobbel’s latest movie about her lasts almost 4 hours. Which is longer than the entire history of the Lich King, Thrall or even the entire Azeroth universe. 
The one character. It’s time to give other heroes more attension and love. There’s no better time for her leaving the stage than in expansion about death.
She won’t add anything important to Void or Titans expansion. Sylvanas doesn’t know about the various cosmic secrets, she’s not important player in this cosmic war. Zoval never told her anything that wasn’t manipulation.
No matter what she does, her return will destroy many people’s trust in Blizzard, which is slowly regained since Dragonflight.
Fun facts: Blizzard shot itself in the foot, by saying that Sylvanas will only leave The Maw once she saves all the souls throwned there. But writers, wanting to play in his own dark Warhammer fanfiction, tell in lore and even gave us quests where we see how these souls are irreversibly destroyed, which makes fulfilling this condition impossible. GG Blizz 
