It would be fun if the "midnight" event took place already sometime between 11.2 - 11.2.7.
For example, one possible scenario:
11.1.5 - Nightfall. "The fall of night reveals her true face. She will bring only ruin." Learn of Xal'atath's true identity.
11.1.7 - Twisted abominations of Old God blood-infused primal beasts, empowered by Elun'ahir's roots, run rampant across Khaz Algar.
11.2 - Head into the dark domain of a fallen world tree. This deadly landscape is primal, and not for the faint of heart. But there is also beauty, with a unique plant and wildlife seen nowhere else on Azeroth. Venture with the Freysworn as they unearth ancient history involving the Keeper Freya, and fight side by side with the Haranir as you cleanse the roots, and protect them from an Old God. The ethereals are heavily involved with the raid, which gives you a glimpse of K'aresh as the Dark Heart is used to bring about the hour of twilight, and usher in Midnight on Azeroth.
11.2.5 - Deal with the aftermath of your adventures into the "rootlands", and say your good-byes to Khaz Algar. Rally its peoples for Renilash.
11.2.7 - Xal'atath's road has taken many twists and turns, but she is now ultimately successful, as Dimensius is awake and on his way to claim Azeroth. (In the meantime, we build
houses - yaaaay!

)
The pre-patch arrives, and the sky darkens (not all of it, but there's like a noticeable part of it that's being covered in darkness above Quel'thalas). Blue, voidy darkness.
Fast forward a few patches and Empress Azshara arrives, defeats Dimensius, and sods off again.