I know many people enjoyed turning the school bully into a sub, but doing so created a fair amount of issues, both from a coding/writing perspective as well as a story perspective.
One of the things we try to keep consistent is personality. The biggest reason for this is because we have many writers who come and go, adding in their own take on things. For them to do this well, they need to know the npc they cameo in their stories doesn't change dramatically. Having Christina be a domme or a sub means everything that involves her needs a minimum of 3 variations (Domme/Sub/Neutral), which can be a real pain in the ass. Things like track team and cheerleader content. Is she a domme to you? Then why would she let you run against her? Is she a sub? Would you really let her race against you? Is she outcasted and no longer a cheerleader? Cheer content would have to remove her from events if she was. Any content that involved her.
From a story perspective, you don't beat up a girl that's been a dominate bully for years and turn her into a sub overnight. That compounds on the problem above, as it would have to come in increments. Say an example of three increments, she barely listens, she starts to listen, she does whatever you say. Now that's 3 more variations of any event that involves her as a sub, then her being a domme, or you haven't done her quest and she is neutral. So now it's a total of five variations.
Another thing to keep in mind is this is all happening in 1 game year, out of probably 8 planned game years. If she ever has her sub content reintroduced, it will be over time, with a complete breakdown of her will, social, and personal life. During UNI is a better time to do something like that, as the social clique isn't as important, and the schoolmates aren't as directly linked.
Right now I am expanding her domme content, which fits her personality, giving her proper reasons for behaving in the fucked up way she does, and along the way am able to explain how Lariska and Lina ended up under her control. I also have a great many other projects to do, and don't have time to make new stories for both paths at the same time.
Does Sveta need more opportunities to be the domme? Yes. Is Christina gonna be her sub? No, or at least not for a long time.