An NDA can take many forms - and we have to undertsand it can be in regards to information on both sides. Company X may not want it's required purity, characteristics, price paid or quantity purchased disclosed and ZEN may want protection from a hostile bid or any unauthorized stock transactions. Issuing a PEA may have no effect on said agreement.
Other agreements may be in place specifically until a PEA is public. Who knows.
One of the questions I have for AE is in this line of thinking - are the handcuffs off after PEA is released? Because at some point the rubber has to hit the road.