As AscendingCanadian says, the recent update made the character files smaller. To be more precise, the recent update split them up into different files. Now, each character has a regular .ab (or _he.ab file, if it's a T-doll whose art was censored), and a _spine.ab file. My guess is the _spine.ab file is what holds their chibi data in the dorm. I don't know. Either way, we're only interested in the regular .ab file because that's where the T-doll art is, so we can safely ignore _spine.ab.
Although, if someone is interested in making nude sprites, I guess the _spine.ab file is what you're looking for.
While the new update did render this mod unusable, I followed red_cloud0's guide despite the new update using PPK and G41 as an example. So far, everything appears to still work. That said, there are some tiny differences, other than the aforementioned _spine.ab file.
"pic_xxx_M" and "pic_xxx_M_Alpha" are no longer used; they are replaced with "pic_xxx_N" that holds the team portrait file. You could still mod in the old team portrait file, but the team portrait background will not carry over. I can't find the team portrait background in any of the files I would suspect it might be found, so I'm guessing the background and T-doll art come as a set. Alpha channel appears to no longer be needed here. Of course, this assumes you even care about the new background, which imo is actually really nice.
According to the uncensored patch instructions, you can also make the game download and use the uncensored images instead if you rooted your phone or emulator. In that case, you'd be replacing the _nom.ab file instead after the game prompts you to download it upon starting up the game. Method's still the same.
So yeah. The mod is now "broken", but the guide remains relevant with minor changes. The team portrait background thing is a bit annoying, though.