WoW Forever players may have missed a hidden entrance to Hall of Thanes
The developers also discussed making some Alliance-only quests available to Horde players.

If you are a Horde player and you are playing World of Warcraft: Forever on Horde as well, you might have thought at some point: "I wish it would be easier to enter the Hall of Thanes". Well, maybe the problem is not being unable to enter, but just being unable to find the secret entrance.
In one of the latest podcasts, the developers hinted that Horde players may have a secret way into the Hall of Thanes dungeon, hidden somewhere around Ironforge. The tease came during the third episode of Dive into Dungeons with Devs, where the team suggested that players might simply have missed the entrance.
Where Is the Hall of Thanes Dungeon
The Hall of Thanes sits beneath Ironforge's High Seat, deep inside Alliance territory. That makes reaching it a challenge for Horde players, who currently have to make their way through hostile territory to enter the dungeon.

The teaser is pretty small in the video, but big enough to make everyone curious. One of the people present says this:
"Hammer and I have not found the secret back door for Horde into Hall of Thanes. So, I haven't run the dungeon yet. I know you are going to say we got Ragefire Chasm right there. Alliance can't do that. So, it's only fair to balance things out. Are we doing new content that 50% of the player base can't access? "
To which the developers answered:
"We want the story in the world to make sense, and they lead some of these mechanical decisions (so making Hall of Thanes more accessible to Alliance), so we appreciate that it can be a bit frustrating, but it's okay if Horde players can't easily access that dungeon. [...] There may not be a Horde entrance to Hall of Thanes. There may be one. You'll have to find out."
So in the end, hard to really say it is a big teaser for a secret entrance. They did not confirm there is one, nor did they give any location or explain how players could access it. They are just leaving the possibility open that there is still something to find.
So if you are a Horde player, you might just need to look better. But you may also be searching for nothing. Hard to say, but good luck with that!
Blizzard Also Wants to Open Up Faction-Exclusive Quests
In the same video, they also discussed making some Alliance-only quests available to Horde players. They already mentioned a few that can now be picked up by Horde as well. This will give the opposite faction a reason to explore content that would otherwise be unavailable to them.
Sadly, none of this confirmed a new entrance or anything like that, so do not assume there is a secret entrance to any Dungeon from the opposite Faction. But you can always dig around Ironforge some more.
For now, the potential entrance remains a mystery.
