"The Context Collapse Problem" by Lloyd Moore https://codegood.co/writing/context-collapse-problem
It sounds like the problem here is that they were trying to solve a people problem with AI. I've worked in exactly these kinds of codebases, where knowledge about the code is a kind of "oral culture" where you have to know who to ask before you start making changes. Sic'ing an AI on that kind of codebase is going to cause a lot of carnage.