I'd say..
Living Forrest
The Pit (I or III)
The Street
Possibly Subway again? If it's somehow different.
Netherrealm (Hell)
Wastelands
Nexus
(Dark) Prison
Reptile's Lair
Wu Shi Academy
Elder God's Arena
Reptile's Lair

I miss the ceiling spike Fatalaties, those were my all time favorite so I really hope they bring those back. Also, they need to remake the Prison, the music was kick ass.

It's been a while since I played MK4 so I had to look them up and I'd like to see the following re-done.

-The Prison
-Reptile's Lair
-Wind World
-Shoalin Temple

This! I loved the Elder God's arena in MK4! Speaking of MK4, what about that stage where its dark and just pouring rain? That would be sick!

Kombat Tomb (upper spikes)

I believe Sub-Zero and Scorpion are fighting in the forest, and it does not look like it's the Living Forest anymore.
I really liked the Living Forest as it was a pit stage and the one tree ate the victim. That was a nice touch.

NRS should really remake the Pit stage and give it the stage fatal it deserves. (MK9 pit was lame, sorry)
Other stages that realy need to return:
Warrior shrine
Kombat tomb
Portal stage
Soul chamber
............................

A stage from MK:D I'd love to see return is Yin Yang Island.

We have never gotten that many Edenia stages, I think there have been like two maybe three over the entire span. Actually or was there only that one in MKA?

Even MK4 which was about Shinnok trying to take over Edenia, did not have any Edenia stages.

All of the stages from MK4 have to make a comeback in some way.

I'm hoping to see some nods to Mythologies as well, but I'm fully prepared to be disappointed.

Aside from that, I still can't believe that to this day there has not been a Lin Kuei Compound arena in MK. That some ol' bullshit right there.

And now that I think about it, I really wouldn't mind seeing what Outworld looks like now that Empress Sharktits is in charge.

Lol you're kidding right? Although that island music was hilarious!

Secret red portal form MK 3 where you fight Smoke with the original music

The lost

The pit 2 with the original fatality

The Portal MK2

Noob's Dorfen

Netherrealm (mkgold)

Skull stage mkgold

Elders god's level mk4

Unused concepts from MK DA in the krypt

MKDA Drummer arena

I'd love for all of the Arenas from MK9 to be updated with interactables
The Portal
Kombat Tomb
Nethership Deck & Interior
Slaughterhouse
Ying Yang Island
Sky Temple
Living Forrest
The Pit
The Street
Subway
Netherrealm (Hell)
Wastelands
Nexus
(Dark) Prison
Reptile's Lair
Wu Shi Academy
Elder God's Arena
Battle Arena