i personally have always liked the idea of a burning version of the DOATEC building stage from 4 that had a cliffhanger into the helipad stage, but cliffhangers are probably gone. Id still like to see it as a drop, tho.
Free Step Dodge
Tokkosho
KasumiLover
I wanna see Genra and Bankotsubo's stages redone with their classic BGM, they're the darkest stages in DOA <3 I also want Freedom Survivor, the bridge stage, and The white storm with heavy snow back
Brute
The Home 
Derock
Definitely the White Storm with some touches of Dimensions and Ultimate versions. Burai Zenin needs both Hardcore and Ultimate versions combined into 1. I also want the L Castle back with more expansion to explore.
Tokkosho
Ahh all some of my fave stages. I'd like to see the concept of Home back but in a completely different stage/setting. I've been waiting for a stage in a shopping mall or something similar, and that would be a hilarious way to incorporate breakables (and the new knock-back from NPCs)
Force_of_Nature
Aerial Gardens, Dragon Hills, Kyoto in Bloom (both), Seaside Market and DOATEC Great Hall would be nice. And NO, NO HOME STAGE lol!