I heard about her book, I also heard about lawsuit threats from Facebook. Facebook is a rich company so a threat from them to sue you is a serious threat. I'm sure they threaten to sue people to try to quash uncomfortable information as do probably lots of companies. Are you thinking she made up the threatened lawsuits?
No, the poster they were responding to was claiming that the whisleblower didn't need to wait for a congressional hearing, that she could have just presented the documents she claims to have as "evidence for a legal proceeding". But such a legal proceeding doesn't exist (apart from the Congressional hearing she was waiting for), there is no one suing Facebook for corporate malfeasance or whatever where she could present some documents she has as evidence while abiding by her NDA.