Well she is a queen if she was a king she would of been decapitated on the spot.
She lost her sugar daddy so I’m not sure she’s gonna try anything just yet
Well, she is a woman after all 
She’s gotta stay so we can /spit at her and get one shot in the first shadowlands raid
Azshara is free and has both her Naga and G’huun’s Faceless and K’thir in her army(yes it was G’huun’s Void Minions we faced in the Shrine of the Storm as the Faceless One Dungeon Boss Vol’zith the Whisperer went on about Pestilence like G’huun’s minions).
N’Zoth is dead and his Faceless and K’thir are all masterless and aimless which makes it easier for Azshara to kill them with the remnants of G’huun’s minions.
Jaina allowed the alliance to use her city as a naval Base and supply depot for their invasion of the barrens, theramore was a legitimate military target. It’s jainas fault for moving her city from neutral to being a cog in the alliance war machine.
We’re murder hobo’s as if we give a damn.
Here is the thing and Blizzard is probably starting to realize and why they let her go. World of Warcraft is in danger of running out of interesting lore heavy characters as One by One we introduce them as loot pinatas removing them from the story unless we pull some weird story arch to pull them from another realm or alternate time line. Azshara was likely let free so they can use her again sometime in the future for another story line.
DRAENOR IS FREEEEEE
JUST WAIT for sylvanas to say shadowlands is free
Taking care of N’zoth was a much higher priority than Azshara.
Picking a fight with one of the most powerful mages in existence in the midst of an Old God plot to warp all of reality into his vision would be a terrible choice.
Yet that effort was paused to gather soldiers and take arms against Sylvanas 
Theramore was long done by the time BfA happened though, and the Horde already blew that city to pieces. I’m talking about the invasion of Kul Tiras. When the Horde attacked Stormsong Valley the Kul Tirans were the opposite of sympathetic to the Alliance to the point where the single Alliance ship that made landfall had to have armed guards stationed on deck.
By my standard? Yeah, Theramore was a valid military target.
Brennadam though? No. Kul Tiras outright refused to ally with the Alliance at the start of Battle For Azeroth. Jaina’s mother tried to have her executed. Kul Tiras was far from joining the Alliance, and that didn’t change until the conclusion of all 3 zones.
So… no. Brennadam, which was attacked shortly after Katherine Proudmoore told us to screw ourselves, wasn’t a valid military target.
I clicked like, but I still hate you for that…
Future content.
Bfa was merely a setback
We kinda did, didn’t we? I guess she is far too charming for us to murder for no loot.
she savin her armies too control the main-lands!
And even if you could argue Brennadam was a valid target, harpooning civilians to their homes to die in front of their children is not justifiable.
If the Horde wanted to occupy the town, fine, but they always go WAY too far in their methods.
Nah blizzard wants stories to continue onto the next expansion even when they don’t really fit.
Its why guil’dan just walked away same with garrosh.
yeah having an alliance base that close to the horde capitol was asking for trouble
no one:
literally no one:
n’zoth:
sylvanus: “yall mind if i attack brennadam for no particular reason?” * doesnt wait for an answer *
Kul’tiras in all intents and purposes was actually against the alliance when sylvanus attacked brennadam. Jaina was sentenced to death, the alliance emissaries were imprisoned, and all ruling houses were in favor of neutrality in the war at the time