I think this is a really tough question to answer because this is somewhat unprecedented territory since this is the first major game that ICSTOR is making with Ren'py (Taboo Request was just a short VN), and it already has, in my opinion, way more in it than the earlier RPGM games in terms of the number of characters and the amount of content they each have. There's also the fact that this game has much more of a narrative than the RPGM games which were more about completing quests than following a story. There's consequences and repurcussions to the overall narrative for doing what you're doing that can lead to very interesting places and some of the different character's stories may also connect with others further down the line, i.e. Linda and Liza, Linda and Judy, Caroline and Violet, etc.
So long as ICSTOR has a lot left in the tank in terms of commitment and dedication to this game, I would hope that they don't try and rush to the finish line or dump certain characters and storylines for the sake of speeding up development. Of the characters that we have content for in the game already, I can see pretty much all of them still having a lot more story and events to be explored going forward that, hopefully, ICSTOR will give us in full and not a rushed final version so they can move on to another project.
That being said, I would also say this: don't get your hopes up for Macy, Delilah, Lily, Zuri and Suri. Macy and Delilah have been added very recently and unless they will tie into an existing character's storyline like Sara or Celia then I can see them ending up as unnecessary tertiary characters. Lily may be Sara's best friend but unless the MC fucks her causing a rift between him and Sara or she gets involved in a threesome, I don't see her being all that important. Zuri and Suri are pretty much done and I don't see why we need to have them back.
