I do not believe anything has changed.
You can start with the most important images:
1) vnsprite.
2) 3 or 4 profile images with different closing (bikini, magic robes, casual).
3) battle sprite
4) resting
5) straight sex (vaginal and anal)
6) gay sex (lesbian)
7) blowjob
![Cool 8)](https://www.pinkpetal.org/Smileys/DarkB/cool.gif)
portraits with base emotions (one each if possible)
9) Combat image (different from battle sprite which is a smaller image to be used in BE, this one is used in training)
10) Nude (at least one nude image without sexual content)
11) Jobs images: Maid, Stripper, Prostitute (provocative), Warrior (combat image can be used here), Waitress, Manager (formal clothing I guess, can be a profile type image).
I this this will make a working pack, rest can be added later.
Maybe it would make sense to make all the image with transparent or simple background. Such a pack may look really good in the game.