“Say what you mean and mean what you say”. Why is that so difficult for normies to understand?

While more manageable by NT people, I think this is clearly a toxic workplace where people are taught to fear their work can’t stand up to scrutiny. So anything that even counts as looking directly at their work is a threat, and any communication must be scrutinized for hidden threats.

Literally what even are the neurotypicals doing

Conversational implicatures. It’s basically the reason why plenty people say something, when they mean something else.

However what that coworker is doing is a bit beyond conversational implicatures, she’s reading too much into what Alyssa said. That’s clear because she then complained that Alyssa didn’t give her enough context - in other words, there was no context to implicate anything, and yet she still saw an implicature there. I call this a “ghost” implicature, dunno if there’s some actual name for that. But to keep it short, the coworker is likely the one to blame for the miscommunication, not Alyssa herself.