Shadowlands is a filler expansion. They recycled Sargeras motivations and the Titan's lore and ruined the coherency of the established lore.
I think Blizzard only had a draft of what they wanted with the Death realm but didn't commit enough with any idea. It is sad because Blizzard games is telling the same story again and again:
- We allied against an authority figure who wants to do "good" without explanation
- We discover we (mortals) are special and unbeatable.
- We decide to fight against each other until the next authority figure wants to change us again.
- Repeat the same formula.
Next, we are going to find out the Light and Void Lords are the true creators of the multiverse, and they were indeed the first ones before separating in 2. We will forgive the Void because flaws are necessary for evolution and growth.
The End