Where do you think WoW’s lore has changed most since the original RTS series?

I was speaking with a friend who played Warcraft I, II, and III, but never played World of Warcraft, or even read up on any of the lore. He started asking me questions about it, and summing up the ~16 years of the lore to someone who loved the Warcraft RTS trilogy really put the game’s story in perspective. Three questions that stood out — What happened to Illidan? Is Thrall still Warchief? The Night Elves are mortal now, right?

“…And then the Titans imprisoned him with Sargeras, and they will battle it out, for eternity.” As I said those words out loud I realized what a strange ending that was for Illidan, and wondered exactly how did it come that?

“Then Vol’jin heard a voice that he thought was the Loa, and so he named Sylvanas the next Warchief.” My friend’s eyes rolled so hard that I thought they would pop out of his head. However, that didn’t upset him as much as when I said, “But now there isn’t a Warchief, they’ve formed a council.” He responded — THAT’S NOT THE HORDE!

But that third question had me going into some detail. Ignoring how Blizzard told the story, it was pretty hardcore. The burning of Teldrassil, Night Warrior Tyrande, the killing of Nathanos, saving the dead Night Elf souls from the Maw, and Tyrande not coming with the player, but seeking revenge against Sylvanas on her own?! He was intrigued, and I could see this was somehow Blizzard finally hitting on an intriguing story with characters of old.

Where has WoW followed the right path with the characters created in the original Warcraft? And conversely, where has WoW deviated for the purists of the original trilogy?