I was not going to discuss the World of Warcraft: The Dragon Isles expansion leak (found here), but then again, I haven’t been above speculation and criticism of the game before, so why stop now? I have read through the notes, and while entertaining, the document is fake.
The leak was reportedly taken from “a private gamedev discord last night.” Okay. How was the Discord accessed? The person would had to have been included in the group. The idea that they are a Blizzard employee makes no sense. What is to be gained by breaking Blizzard’s NDA to post about the next expansion, other than being fired? Likewise, if they are friend or family, why risk the dev’s job for the same reason.

Having worked with different IT developers over the years, they are generally very detail-oriented people and do not employ descriptors as “crazed”, “biggest Blizz have ever produced,” and “super fun” in documentation, but they do use proper punctuation and grammar. If these were developer notes, they would have been formatted and detailed; not written like a fan fiction outline.
As for the story, the Dragon Isles is a reasonable direction for the 10th expansion. It expands Azeroth with a new landmass and returns dragons to the story for what should be a celebratory event. Wrathion did not make the trip to the Shadowlands, and it would be interesting to see what the black dragonflight have been up to in our absence.

Not matter the location of the next expansion, the World-Soul will be at the center of it, as we move closer to the apparent looming war with the Void Lords. Azeroth, the maturing titan, has experienced a lot of trauma from the end of Legion through Battle For Azeroth. The World-Soul’s emergence opens a new chapter in the planet’s history, and sets up the potential Void War for the following expansion.

I only have brief comments on the listed game features. Adding black dragons as a player race is no more ridiculous than pandas, and they seem to have worked out . I support updates to the older zones. The Burning Crusade starter zones still exist as separate instanced zones from the rest of the post-Cataclysm world. This should be updated. The “World Bond” ability sounds like another borrowed power system. I don’t see that being very popular after the Shadowlands push back. “World Shaping” sounds like something for a single-player RPG. I don’t know how it works in an MMO with many players utilizing it.
For being developer notes, nothing is mentioned about character or class progression, new talents, balancing, dungeons, raids. I would think this would be something a developer would want to share.
By posting these details as a leak instead of a story idea, the author has garnered a lot more attention and fired up the speculation machine. If the interest motivates Blizzard to move up their expansion announcement plans, I will consider it a move well played.