All she really did was blow the whistle. For that, she was banned for "abusing a relationship", in a thread where she was trying to call out the behavior that lead to the necessity to make the thread in the first place.
Maybe she really needed to be banned for having that access (or maybe the person who gave it to her, maybe?), I dunno it's not my site and I don't make the rules, but dropping that ban on page four of a thread about how the feelings and emotions of trans people aren't being heard or respected, especially by staff, and then pretending like the staff are the real victims here, sends a very, very bad message.
It also essentially proved correct every allegation she levied in that post, or at least made it essentially impossible for a whole lot of people to see it any other way.
I think maybe there's a bigger problem than KetKat, and that focusing on her having "inappropriate access" to a freaking Discord server isn't really the answer.