Not to minimize or justify any of Bloomberg’s abuses but the use of NDAs to silence employees who accept a settlement is standard practice at all big companies. Not just for sexual harassment, if you take an early termination payment you typically have to sign a confidentiality agreement.
I’d bet it would be impossible to find even one Fortune 500 company that has not paid off employees who complained of sexual harassment and required them to sign an NDA in return. Lawyers love these things and they run the show.