Unions agitated against this, and got it rescinded.
My question is -- how did the Union action serve the employees? Although it might be nice to vent against someone who fired you, if push came to shove I would rather have an extra couple of thousand dollars in my pocket. So now, no one has to sign an NDA, and no one is getting the extra bonus. But I don't see how benefits from this. Read the whole story here.
NB. Amazon is also interesting because it set up a trust fund of stock, whereby laid off employees may benefit from some of the stock market bounce they helped create by getting fired.