People seriously underestimate how much Scourge there will be in Midnight.
Is it because of recency bias? PTSD from Shadowlands? Or something else?
But are people not aware that the entire southern kingdom is firmly held by the Scourge? They even have a huge fortress in the region called Deatholme. Then there is also the Death Scar, a massive scar bisecting the entire kingdom and infested with Undead.
I don't know if people are somehow traumatized (lol) by Shadowlands to forget about the Scourge, but it's clear that the Scourge will be a B-plot of the expansion. Just because the Lich King is destroyed doesn't mean they'll remain mindless forever and it actually makes so much sense to involve Drathir in Midnight.
1) The Void Elves found Telogrus Rift because they were studying Drathir's research of the Void. He was a necromancer with great forbidden knowledge of the Void.
2) The original traitor who allowed the Scourge to bypass the Ban'dinoriel and lay waste to Quel'Thalas.
3) He is a Lich in all but name, having been resurrected multiple times.
Expect to see Drathir and the Scourge in Midnight as B-plot.