Yeah, I wonder why they don't at least give us more U2 and 3 maps. Even just the layouts from those maps with assets from U4. I'd be more than alright with that.
You know what I'd be happy with, variants of the current maps. You know how it starts raining on pirate colony? I'd be alright with a daytime only version, a rain only version and and evening version of that map, and other maps as well...Something that simple can add a decent amount of variety. Rooftops in the day, Auction house at night...This is something Assassin's Creed did with it's maps and it really made a huge difference and it felt like there was a considerable amount of extra content because of it.
I'd also like normal Survival to be added, I really hate that they're 5 rounds. I want to play 10+ rounds on train wreck, I want all the maps added to it as well. Give us endless rounds with limited lives or even just 10 round customization options.