Introduction
In this season of leaks, I decided to go ahead and put forth another possibility for an expansion; Undermine: The planned continent from Vanilla WoW that due to time constraints was not added in the final release. Please note, I am not saying that Undermine is the next expansion, I am saying that it is a future expansion prospect due to its basis in lore, and statements made by Blizzard over the course of WoW's history.
Background
Undermine is the Goblin metropolis beneath the Island of Kezan. Its lore dates back to WC3 (if not earlier), and was actually planned as a continent in Vanilla WoW alongside a playable Goblin race. Undermine is the home location of various Goblin cartels, the incredibly wealthy Goblin trade princes, the trade coalition, the Venture Company, the Tinker's Union. In addition, there are various underground towns, slave markets, lavish palaces, and glass tunnels along the ocean floor that out of the main land mass that connect to underwater "island" caverns and other Goblin holdings. All of this was originally planned for Vanilla, but obviously the amount of work required was simply beyond the scope of the design team at the time;
https://www.youtube.com/watch?v=L77uPm5cuTo&t=4257sBlizzard originally wanted to include Undermine in the original World of Warcraft along with goblins as a playable race, with Johnathan Staats describing it as "tinker town" and "crazy". However, as the team did not have a lot of goblin art assets, building the goblin homeland would have required "a ton" of work, leading to both Undermine and playable goblins being cut from classic WoW.[15]
Goblins would eventually appear as a playable race in Cataclysm, and a small portion of the planned continent would appear as their starting zone. Since Kezan was devastated by Deathwing's awakening, many thought that Kezan along with Undermine were destroyed. However during a Q&A, a Blizzard developer stated that not only is Kezan and Undermine intact, but we would return to this location at some point in the future;
http://wow.joystiq.com/2010/10/22/bl...panel-liveblogAt BlizzCon 2010, Alex Afrasiabi said that the goblin starting zone was only "a small segment of the actual whole' of Kezan", and that the goblins "did want to go back to Undermine and the other goblin land holdings, just a question of when."[30]
Some of this was accomplished in BFA, with Kezan being considered a hotspot for Azerite, and the MOTHERLODE dungeon and Crappolis being feature. So while we got to see a few more land holdings, Undermine has still not been revealed.
Finally here's a brief article from Endgadget mentioning areas of Azeroth that at the time hadn't been explored in WoW. Interestingly, these locations were Undermine, Broken Isles, and Pandaria. As we know, we have Pandaria and Broken Isles as locations for expansions. Undermine still has not been featured in the game;
https://www.engadget.com/2011-08-07-...-pandaria.html
Reasons to Implement Undermine as an expansion
There are a few major reasons to implement Undermine, some of which I've already mentioned, but here are some things that immediately stick out in my mind;
1. It is one of the last continents from old school Warcraft that hasn't been featured in the game (everything else is Islands).
2. It would be an underground expansion, which gives players a locale that they have never experienced in previous expansions.
3. It opens up the possibility to incorporate the final 2 WC3 RTS heroes (Tinker and Alchemist) as a WoW class, since they are both Goblins.
4. It allows for a grounded expansion on Azeroth, something that Blizzard and the userbase seemingly desire after cosmic-based expansions.
5. Despite it being grounded, the rather unpredictable nature of Goblins and Gnomes allows the art team to really go wild with ideas.
6. It generates lore for races that often don't get much focus in WoW, and is a different side of the WC universe (Steampunk vs high fantasy).
Possible hints at future implementation:
1. Gazlowe taking over the Bildgewater Cartel and becoming a trade prince.
2. Kezan found to be still intact during BFA.
3. Gallywix missing after Sylvanas' abdication.
4. Hints of the Tinker class on Island Expeditions in BFA and Exile's Reach in Shadowlands
5. Kezan remaining a major source of Azerite, which indicates that Undermine would also be a major source of Azerite.
6. Blizzard inexplicably tying mechanicals and dragons together with the Timeless Mechanical Dragonling, and the Ironscale Incinerator post-BFA.
7. WoW Undermine April Fool's gag in 2021 by user Handclaw (long-shot I know, but that was a pretty extensive joke requiring a lot of art assets).
Anyway, that's it. Thanks for reading. We'll see if we get this in a future expansion. If not the next one, perhaps a few expansions down the road. There is also the possibility of it being added as part of an expansion.
Resources:
https://wowpedia.fandom.com/wiki/Und...able%20mindset.
https://wowpedia.fandom.com/wiki/Kezan