To add to this, some other things that were built up in BtS and never went anywhere:
- Sylvanas’s plan to raise all the inhabitants of Stormwind as undead (seems counterproductive if you’re trying to send souls to the Maw to feed the Jailer)
- Azerite’s effect on the mind of a person who touches it
- Azerite in general–it was built up as this all-important resource that the Horde and Alliance would be fighting over, and in the actual expansion, only Magni and Lady Ashvane really seemed to care about it
And I’ve been searching for the quote, but I know I remember some dev saying that BfA would wrap up the faction conflict for good. At the time, I expected that we’d end the expansion with both sides having Azerite stockpiles and mutually assured destruction.
ETA: Found the quote: