I honestly hope she never talks about it. I don't need validation in my suspicions, and no matter what the cause was, it's embarrassing, unprofessional shit that is likely better off memory holed.
I started off in the camp of believing that she likely suffered a series of unfortunately timed woman moments or an actual diagnosable mental health crisis, but I don't think that fits well. There have been a couple comments from talent that indicate that management likely knew that there was an impending issue before the 10/25 date was set publicly.
After digging around off and on for ~the last week though, my personal rrat is that her (spiritually boomer) parents likely physically intervened to prevent her from working. As in, they took her hardware and destroyed or refused to return it.
Total tort mess for the fishman if I'm even close to correct, and if he had to pull the trigger on some sort of legal maneuver/pressure, he would have known for sure at that point that things weren't going to resolve before 10/25.