Burning still happens due azerite stored in the tree from silithus the Alliance and nelfs mined.
But in fight of malf vs sylvannas saurfang still aids by throwing axe in back and then Sylv fights Tyrande while Saurfang goes away (told to by sylvannas)
Ultimatly a lighting blast from azshara in heat of battle sets fire to it and Horde belives night elves did it to drive them away and Ally thinks horde and sylvannas did it.
And burning is as whole less severe. Most civilans wouldve been out alreayd, few die from staying behind or getting struck by the lighting.
And Goldrin aids with defense of their lands aswell as Cenarius but both arrived to late to stop/prevent it but after they came and burning of tree horde had to retreat.
Malfurin is heavly wounded and With cenarius help of cenarius gets healed but not enough to fight yet, and they over expac heal their lands and the tree.(except azharas lighting scar which will take years to restore)
id make sylvannas sitll use plague at undercity as last resort after Tyrande and Jaina show up, but saurfang still stays behind and ultimatly wounds Anduin heavly and he has to be brought away asap to get treatment from velen and other healers.
Jaina and Alleria help escape with portals.
Saurfang gets subdued by alleria and Turalyon.
Tyrande later still goes nightwarrior and kills the valkyr and 99% of horde troops there and while nathanos escapes he gets shot of out sky and his body is half burned away by moonfire and she destroys some ships aswell. But she then is exhausted from pushing herself bit to hard (plus she is new to the dark side of elune powers)
Nathanos wouldnt be seen for quite a while and is presumed dead but later shows up in zandalar found by some fishers.
Id make the horde not fall for stupid trap and sending all their military away from dazaralor.
Some still go and no night elves are there outside few but not loads. More other troops.
Id make them not destroy entire fleet and have rastakhan be pushed back and defeeated but not die and talanji take a hit for him then back up arrivés and Alliance still retreats after temple rumbles from rastakhans fury.
And id make the loa aid more aswell in the defense.
They still fight Jaina on seas and ultimatly Talanji gets fatal hit(or is just in coma for long time) there combined with her earlier wounds.
Jaina is alive but actully has a slightly cracked staff( she pushed herself freezing a part of the ocean which is hard) and have a few scars left from the fight.
Id make Baine just sit out the war on kultiras and zandalar .
And focus on defending his homeland from Alliance and some angry night elves aswell that wanna kill the horde(as they think its all hordes fault for the tree)
Ratsakhan fully joins the horde with zandalari. Weakend but still strongest/biggest navy there is And bwonsamdi dint betray him and he tries to convince rastakhan to give him part of his soul or so or alot of souls in general to save his daughter where rest of loa failed.
Also id make Kragwa Eat some Alliance soliders in a cutscene while he hops after some ships but then returns.
Alliance has to regroup and they try to push for some important soliders back or else saurfang will die which they have captured.
And be strive between the nelfs, lightforged,void elves worgens and rest of Alliance, those who wanna go to extremest ends to end them and others who wanna regroup get more organized again.
Azshara’s nagas start invading over the world and ultimatly the sea opens up like does now but its lot grander of a underwater city and zone (more like vashjir + surumar and Nh)
Tyrande is there she comes to check it out after heearing or seeing azshara open the see, malfurion who isnt fully recovred stays in darkshore to defend and work to heal the tree with cenarius.
Also id do no ashvane there really, she’d be there but quikly kileld by the naga after they got her plans for more weapons. Also no jaina there.
Azshara still lives and escapes but thalysra and tyrande bond bit closer but both still return to factions And both help their troops escape from there with teleportation for thalysra and tyrande making some highborne makes make portals back. and sea beings to close again but the hearth of azeroth was aslo broken after the fight and it collapsed the prison of n’zoth which makes so he couldnt escape at all.
Then war continues and Night elves have since gotten lands back ,malfurion is healed the tree is restored and no fire anymore but still has some visible dmg from azsharas lighting that will still need time to heal on its own.
They get Most of Azshara lands aswell and Orgrimar is under siege aswell by Alliance and horde has to defend.
Where nathanos dies and ultimatly is little of ogrimar left after Tyrande helped the siege but she pushes herself overtop completly destroying the city(like few small parts would still stand basicly ruins).
Sylvannas gets heavly injured in fight with tyrande but both live ultimatly.
The orcs move Further back while only area of horde land is part of azshara where galywix is.(see it as him making deals to keep it from horde and Alliance as his own)
On EK horde gets ghostlands fully and plaguelands outside argent dawn/crusade area. Arathi aswell.
And silvermoon is fully restored by now (as is exodarand the isle its on) and has extended outposts in ghostlands adn runestones for barrier to protect themself. And 1half is largly nightborne while other mostly Belf.
At end of war sylvannas steps down as warchief as Rastakhan takes over(who has become better leader aswell) and zandalar is the captial of horde But Silvermoon is now exapanded is is big port city of horde along with zandalar and has all the magic stuff and tons of portal networks and was aslo sued to keep civilains safe in their lands from other races.(which fits for lorethemar keeping his people as priority and explains why they arent seen all over).
Ultimatly war ends as both cant push it anymore due troops. But Anduin is aslo after the war removed as leader and its more of council instead of high kin as Genn,Alleria and Tyrande did way more during war then he ever did. ANd he just stays king of Stormwind.
And saurfang at end of war woulde been released but he retires from active fighting.
Also Calia stays death and no lightforged undead.
Mechagon id cut and save as for after all rest and is actully undeground from the vault not on Island.
thrall does come back in end for new warchief rastakhan and to help rebuild a new captial for orcs further down Kalimdor.
Cenarius will often patrol the night elf lands aswell to stop a invasion ever being a thing again in the nelf lands.
The sword id keep around for now aswell but the bleeding is stopped and is kept watch over by magni,earthen ring and cenariun circle and some ancients.