Now, more than ever, I have this feeling that WoD was simply a filler expansion. A wet dreams come true for someone at Blizzard. A way to establish old lore characters that will be important in their cinematic universe to come. But as a story for the game? For this game? No, not really a good choice.
If Blizzard was smarter, they'd make this alternate story into the Warcraft 4 RTS game. Sold millions of copies, established a completely new timeline and could milk and milk out of it. While the WoW could go on with this Legion / Azshara thing much more.
Just imagine if we ended Garrosh in SoO. We would get Azshara expansion with many of the elements from Legion xpac and then we'd move on to the Legion itself. We might have gotten the same bad gameplay decisions like garrisons etc. that we got in WoD but as far as the story goes, everything would be much smoother. Much more elegant. What do you think? The least I can say, at last we are back on the right track with this one.