I don't think you have to despair over the availability of corruption content, I just think it's going to come in specific forms from specific characters.
With Holly I just don't see her changing away from her empathetic and generally sweet personality, so while I won't write off the option to have content where her and Ian are sexually involved without romance, I just don't see Holly cheating on Ian deliberately. We see how she despairs over catching feelings for Lena on the romance route, I don't think that core to her character will ever not be there. So, sure, sexual openness and casual sex with her and Ian on a route like I suggested I think will be possible, but I don't think deliberate cheating, at least not where the kink is emphasised specifically, will happen with her, not unless Ian himself introduces it as a kink and is into it.
In a similar vein I think Cindy will have specific content depend on the route you pick and it won't really deviate from that. If you romance her correctly and don't cheat on her, she won't cheat on Ian either. If you emphasise the cheating kink with her and Wade, then sure it would come into play there and with Axel too. I'm still not sure Cindy would actually enjoy the humiliation, but I haven't actually played the route so I don't know if there is any tonal shifts to indicate that she herself thinks cheating on Wade is hot.
If you deliberately half-ass her route trying to get her with Axel, against either Ian or Wade, I'm not really convinced that a route will come that relates her to any specific humiliation kinks, I think Cindy would focus her attention on her new relationship and her new career. Axel might give Ian some heat depending on his relationship to Lena, but outside of that we don't really get any indication that he really gives a fuck what other men think of the women he fucks.
Alison very specifically is already involved with exhibitionism towards Ian from very early on, so there is no arguing some of her content will continue to head that way.
