Its really the only one left that hasnt returned in some way shape or form to the point it even moved backwards, no longer being its own zone. Stromgarde was reformed in BFA, from its shadow in the form of the League of Arathor, then short stint as a ‘Forsaken’ kingdom, Kul’Tiras came back as well during the same time, Gilneas came in Cata, Dalaran popped back up in Wrath and continues to be its floating city for the Kirin’tor, Stormwind is, well, Stormwind, and Lordearon belongs to the Forsaken (bite me). Alterac indirectly had some development during BFA, simply being stated that the Forsaken control the area and use it to sustain Hillsbrad.
The TLDR background is it betrayed the Alliance of Lordearon to allow the Horde through their territory due to a mix of disdain for Stromgarde and seeing the, perceived, writing on the wall for their defeat. Obviously then found out and defeated by the Alliance, the kingdom was brought to ruin, presumed and various corrupt nobles started the Syndicate and struck out against the then almost equally ruined kingdom of Stromgarde - though also ultimately and mostly defeated by the Alliance and Horde.
So what do we do with it? It was a sparse zone in Classic, and an even sparser zone when they redid it in Cata. However, like many zones in Warcraft that are criminally under developed, its fairly critical when you actually look at it. Alterac remains the only major land route, and most direct, to the Plaguelands without going through Forsaken territory. Whoever controls that pass controls a lot of travel, or lack thereof if thats the direction they choose.
In general I’ve been a huge supporter of supersizing the zones, Suramar has been my go to example and really shows how Warcraft can do a zone well from ruins and wildlife to urban expanse. Becoming an independent, better/well designed, zone is definitely the starting point.
Clearly potential for a Forsaken and Frostwolf zone - both rebuilding the old Alterac Ruins/City into a shared hub, if not a real city again even if just in redevelopment with a mix of architecture. In this deep dive I did, there is a Death Knight in WC3 named Baron Peranolde - and personally would love to bring him into WoW as the old Aiden Peranolde, the king that betrayed the Alliance to the Horde, now serving the Horde as Forsaken. It offers great parity/a point of friction against Danath Trollbane given the two kingdoms’ history and is a nice little shoutout to the fan idea (regardless of agreement on it) of trying to make the skinny humans a Horde allied race through Alterac/The Syndicate.
On the Alliance side we still of course have the Stormpike, as far as Im aware AV is still going on so might as well keep them around and make them a little city/Dwarf fort in the outer ring/fingers of Alterac near Hillsbrad. Beyond the Dark Portal lists Isiden Peranolde, Aiden’s nephew, as the successor to the Kingdom that Genn supported. Throw him in there with some Alliance attempts to reclaim that kingdom as well coming from Stromgarde as a launching point. I personally wouldnt go for a full on assault bulldozing through Tarren Mill, rather a guerilla war in the Uplands to starve out the Horde through, what we can call, loyal Syndicate forces to the human Kingdom of Alterac (presuming they get like a pardon from Genn).
If we really want to get messy, throw in Lord Ravenholt and potentially some random Scarlet, Valea Twinblades probably best as both a named champion of the Crusade and from Alterac, at various points and we have a good ol’ fashioned succession crisis that we kinda missed out on in Stromgarde.
Others? I’d just hate to see a zone with such potential be wasted. Speaking of zones with wasted potential, the hell should we do with Deadwind Pass and Karazhan down the road?