Except we encounter both Kael’thas and Zul’jin and they both interact with us, even in different ways depending the race of your player character lol
That was them, but the problem is that there is a two fold process
The Arbiter decides you are to go there
Your sinstone is created in Revendreth but the venthyr, not by the Arbiter
ie there’s no way of knowing the reason why the Arbiter sent you is the virtue the venthyr recognize, because the Arbiter doesn’t send memos, and the venthyr are not the Arbiter
Well it is implied that the Venthyr can sort of see the sins of mortals or their spirits of some ways. Because when you ask one of the first Venthir’s you meet about Sinstones he mentions that yours was not created yet because you are still alive and you still had time to “correct” some of your ways.
Ironically this implies that the World Reaper who lacked a conscience was sent to Revendreth because she had more than enough Anima with which to let go of her Sins due to her sheer scale of villainy!
In otherwords she was soooo Evil and over the top about it she was redeemable!
Well, with that being stated - If you look off the edge in each zone you can see other distanced buildings, trees and castles etc in the fogged distance. Lorewise I’d wager the ‘zones’ we visit in the Shadowlands is the ‘central’ parts of those respective realms.
I didn’t know this was a thing, and now I hope it’s what we get in the inevitable post-launch zone. That or something tailored to orcs and their afterlife preferences.