What exactly should we say? "Hey Tim, this unnamed ex-employee, working on an unnamed and extremely vaguely characterized project in an unnamed organization, is accusing unnamed co-workers, managers, and HR-representatives of perpetrating truly appalling abuses on her. You should look into this at once!" ?
It's a difficult situation for the original author; I understand their desire to remain anonymous for their protection, and I understand their wish to have their allegations investigated, but I don't see a good way to reconcile these two goals, and especially not a good way to recruit allies for the second goal.