My Wishlist - I'll probably edit this to add more as I think of new things.
No Microtransactions - Why were Time Krystals even a thing? Why was there a time limited shop to begin with?
Less Special Forces Characters - I find them boring and redundant. Why do we have Sonya & Johnny if we have Cassie. Why do we have Jax when we have Jacqui? That's 3 slots that could be opened up for infinitely more interesting characters like Havik, Ermac, or Smoke.
Chaosrealm & Orderrealm - We need to spice things up. Bring in Hotaru & Darrius. Introduce a new Chaosrealm character along with Havik. We've spent so much time with Outworld & Earthrealm in the current timeline, that we haven't even scratched the surface of all that the Mortal Kombat universe has to offer.
Keep the MK11 Gear System - I hated Injustice 2's lootbox mechanic with a deep passion, and I hated that you couldn't have EVERY piece of gear in ur character's inventory. So I was absolutely thrilled with how MK11 did things. You can see every single piece of gear & how to unlock it. Of course, it'd be cool to have even more customization, and some gear pieces were absolutely pointless (Looking at you, Noob Saibot's shadow...) so it'd be neat if we could somehow mix in Injustice's level of customization with MK11's gear system. If that makes sense. Or at the very least, give us more skins. We essentially would have 1 unique skin with 9 recolors. So there's only really like 6 unique skins. And then you have Skarlet who had 3 of the same skin with various pieces missing like her goggles or a piece of fabric. It felt lazy.
No More Variation Abilities - We can keep the "Variation" loadouts for intros, victories, cosmetics, etc. But no more abilities. I do like the idea that you can make these characters play how YOU want them to. But not when it just makes the characters feel empty and like there's something missing. Like, Sub-Zero's Ground Freeze being banned in competitive play. And I can't even describe how much it pissed me off that I couldn't have all of Rain's classic moves in a single variation...
Towers of Time - Having a mode strictly for offline play is great, especially when you can let the AI grind through the towers and unlock cosmetics for you. (This is probably one of the best additions. Although the grind should be removed period, it helps when you can simply let the AI grind for you.) I honestly don't think there's anything I'd change about it. Some of the AI + modifiers could be insanely annoying though...I'd tone that down a bit. But I loved the holiday events. Hate time exclusive gear and skins though.
Krypt - More fun Krypt adventuring, less grindy timewasting. The MK11 Krypt was fun. Exploring iconic stages, characters making cameo appearances. It was fun! However, the grind, was not. I like the puzzles, the traps, the stealthing around giant spiders, etc. But the notorious 50 fatality per character head grind was...without a doubt...a choice. Luckily, I participated in the great Krypt head exploit...but others weren't so lucky. Let's not do that again.