There were very good reasons not to do any of the above.
They weren’t interested in running those stories as more than likely the majority of the players who really don’t care about the lore would have wanted more exciting things to do.
Blizzard has told us repeatedly that they were tired of doing work on capital cities that no one was using. They had said that there would be no new race capitals made and that they’d start looking at pruning the unused ones. Darnassus and the UnderCity were two of the least traveled locations in the game.
They had also said that setup for BFA to was a consolidation of factional territory in Kalimdor and the East Kingdoms. That made Darnassus and the Undercity prime targets for the chopping block in addition to the reasons listed above.
It is not a matter of “dumping” on the Night Elves or punishing players who took those araces, nor does that apply to the Forsaken. As as been shown almost every race in the game has the same or greater levels of tragedy in it’s history. Both the Draenei and the Orcs for instance, lost their entire planet. The trolls lost their archipelago, and the Blood Elves and Worgen had their homes ravaged, and I can’t even count how many Human kingdoms including Gilneas have fallen, not to arise again.
NE players on this forum need to dial down the persecution complex a bit.