Yes, if the main reason were that the accused would not know who it was, I can see your point.
If it’s someone who doesn’t want their face splattered all over the media, that wouldn’t be the case.
Her intent was to prevent him from being seated. I think she wanted to do it without having to face public ridicule.
Interestingly, Joe Biden — who was the chairman of the Senate Judiciary Committee at the time — was adamant that he would not allow any information from Anita Hill to be entered into the committee’s records on the nomination if she remained anonymous. That would have been a big no-no in anything remotely resembling a legal procedure.