Turnro, this was a great campaign and that ending was just really surprising and I never saw it coming. Meanwhile I really loved how you laid the foundations for the reveal in Jeopardy of the Horde and showed in Resurrection of the Scourge how everything came together. I know why Thrall and the others thought the Night Elves were helping a demon, instead of imprisoning one.
Meanwhile I rather liked how Azgalor's position of the leader of the Burning Legion was being usurped from him even before he was killed. This could be seen with how he was surprised that so few of the Legion entered Azeroth with him and with how the Pit Lord (forgot his name) and the fel orcs spoke of Eredon in the Fel Orcs Ch. 5. In all honesty I'm convinced that the fel orcs will appear in the full version of Malfurion's Quest.
Now while the campaign was good, I found Dalvengyr's arrogance to be too surprising. I get that they successfully beat some of the Horde forces that had been involved in Azgalor's death, but they didn't face Thrall and they felt they couldn't handle Cairne and his Tauren. As such I had a hard time understanding why Dalvengyr felt so confident and assured about the Scourge beating everyone. I also thought it was weird to see the ghost Antonidas in Ch. 8 considering he didn't die in Dalaran.
Though I have to admit that one of the things I really liked about the campaign was that we got to see characters from the earlier campaigns such as Ajar (who I enjoyed playing again), Arthas, Drek'thar, Samuro, Rokhan, and Cairne. As such I began to wonder what was going on with the characters from Rowan the Wise and if we'll ever see any of them again.
Now I do have some suggestions for you:
In Chapter 7 three of the bases are the same color, so maybe you could change the Elven corps to teal and the Kul'Tiras Elite Troops to green in order to have more variety.
In the same mission the Stormgarde Brigade feels like the odd man out since they don't have a hero. So maybe you could give them a paladin or something.
Since we are seeing characters from Jeopardy of the Horde, maybe we could see some characters from Rowan the Wise. For example instead of a random Archmage in chapters 4 we could fight Nathan the Mighty (leading an expedition for more treasure in Northrend) and Tara the Magnificent could be guarding the book of Medivh instead of the ghosts.
I also have two questions for you:
Since Azgalor needed the demon to die in order to enter Azeroth how did he enter when Eredon lived?
This question is more out of curiosity but what made you decided on using Dalvengyr as the third Dreadlord?
Though it's a late reply, but I would wish to clarify that the same colour for three bases was most likely a bug. At the start of the chapter, the five bases are all of different colours (use iseedeadpeople to confirm). It was after the optional quest where Dalvengyr killed the red dragons and transformed them into frost wyrms for the Scourge's use that the bug occurred and transformed two of the bases to the same colour as another.