I think that's the crux of it! It's kind of a testament to the writing quality of the game as a whole that as someone who A, is into fatal vore, and B, has never particularly cared about Cat, I was rubbed the wrong way about this whole situation enough to really dwell on it and actively search for discussion about it. Because ultimately, while Rachel so casually and deliberately digesting her was definitely kind of a tonal shock compared to how the game usually handles that sort of thing, I think the real issue that made it feel bad is that it honestly feels like Cat got character assassinated entirely to make her fate seem somewhat justified. She had issues being an enabler and a bit toxic about her feederism before, but that abruptly got turned up to 11 in the harem encounter, then she doubles down on that behavior instead of learning anything from her initial karmic punishment and the narrative seems to shift to blame her exclusively for The Rachel Incident (even though Rachel was very much the instigator there and shares the blame even if Cat did get carried away as it went on. She warned Rachel she would and that it was a bad idea at the start lol). Just felt very off, and I really hope she does get rescued from The Ass Zone(tm) at some point seeing as it was even pointed out there are at least 2-3 already established characters that could probably do so. Because if not and that's actually it for her character, that's not a "hey, at least she's not actually dead!" reassurance, that's a fate worse than death lol.
Still really enjoying the game regardless though, Wires's backstory was really captivating and well done :)