Holly almost certainly will get one more outfit if her change variable is high enough, probably similar to Ivy's or Lena's lust outfit. Holly is the only one I'm certain has one more big change coming, the question will really be how. Will she actually get a tattoo? Piercing? How will her hairstyle change? Outside of Allison dying her hair and Holly letting her hair down, instead of in that messy bun, hair styles haven't been explored as a way to update a characters silhouette. I'm hoping for another good girl outfit too, if she's dating an Ian or Lena that haven't caused her to be more like Lena.I could perhaps imagine one more clothing change for Holly, if her change variable gets to go higher or perhaps if she remains single.
Any other character is a bit of an open question, Lena is a POV character so I wouldn't be entirely surprised if her lust stat accounts for a further wardrobe change down the line for her casual wear.
Alison might depend on her routing and how Ian agrees with any changes if she's with him, but Cindy and Cherry I am not sure if we'll see them in anything besides the occasional one-off outfit change like Cindy with her black/white outfit when going to Axel's. Emma will probably continue with the more feminine style if encouraged, though it's hard to say where that will go. It would be kinda fun if it can escalate, I imagine her in frilly things and wearing a cute little pink bow in her hair!
An idea that just popped into my head that I now kind of fancy. If another round of clothes get unlocked for Ian and Lena, but is only available if they have level 10 in a stat. We're enough chapters in that at least one if not two stats can be at 10 with others not far behind.