So far we will see 6 afterlives in Shadowlands:
Bastion
Revendreth
Ardenweald
Maldraxxus
The Maw
The Other Side (AKA Troll afterlife)
The last one is a Dungeon, not an outdoor zone.
But if the Shadowlands are supposed to be infinite, 6 is far too little. FAR too little.
So I think there should be more, even if they are just glimpses.
And how could Blizzard do such a thing and still deliver this expansion in the 2020s?
Well, remember when we went to Argus and used portals to go to different planets and flank the Legion there?
We got a glimpse of 6 different worlds. Aurinor, Bonich, Cen’gar, Naigtal, Sangua and Val.
The zones we could explore in those worlds were tiny and self contained, but they were there and they did their purpose to show there were other planets suffering from Legion Invasions. We got a glimpse of a larger universe in a content patch.
And that’s not all. We also got to see several other worlds like Dreadscar (the Warlock Class Hall), Mardum (Demon Hunter Class Hall 
), Niskara (quest scenario), Elunaria (part of the Antorus Raid) and Telogrus (Void Elf starting zone).
That’s 11 planets we got to see!
I feel like Shadowlands should do that. Show us a bit more of the specific afterlives in small ways. Give us the feeling that there’s more out there than just different fates for everyone in the universe.
And Goblins should definitely get their own Goblin heaven that is all about GTL (Gambling, Tinkering and Laundry!)