During the fight
The friendly NPCs that should have come out of the tunnel should be fighting undead to stop them from getting to the party. This battle is not occuring at all.
Friendly line of defense can be breached by the undead it is suggested that the strength of the defense is determined by nubmer of freed slaves.
It seems the undead are the same as those that players meet on their way across the tunnel.
After the boss dies
Afer the boss is dead another event should occur, where Sindragosa comes and kills most of the friendlies by Frostbomb. Players are saved by Jaina/Sylvanas.
Video from Classic with great commentary: https://www.youtube.com/watch?v=NsbILjGXrak&ab_channel=Harldan 14:20-15:20: start event + explanation about freed slaves
Missing friendly NPCs: Freed Horde Slave 37577, 37578, 37579 Freed Alliance Slave 37572, 37575, 37576
https://wowpedia.fandom.com/wiki/Scourgelord_Tyrannus#Adds_From_Behind Video from Classic with great commentary: https://www.youtube.com/watch?v=NsbILjGXrak&ab_channel=Harldan 14:20-15:20: start event + explanation about freed slaves 15:45-15:55 and elsewhere throughout the video: the battle at the tunnel in HD 14y old Horde video; 7:27-7:59 https://www.youtube.com/watch?v=5E_E-w3KxxY&ab_channel=Rill 14y old Alli video; 8:12-8:16 https://www.youtube.com/watch?v=dmam_1SvakY&t=8s&ab_channel=Rill
https://wowpedia.fandom.com/wiki/Gorkun_Ironskull#Quotes https://wowpedia.fandom.com/wiki/Martin_Victus?so=search#Quotes https://wowpedia.fandom.com/wiki/Sindragosa?so=search#Wrath_of_the_Lich_King (2nd paragraph)
Classic video;17:25 onwards: https://www.youtube.com/watch?v=NsbILjGXrak&ab_channel=Harldan 14y old Horde video; 8:20 onwards: https://www.youtube.com/watch?v=5E_E-w3KxxY&ab_channel=Rill 14y old Alli video; 8:40 onwards: https://www.youtube.com/watch?v=dmam_1SvakY&t=8s&ab_channel=Rill