That's a great question, Bill!  I'm very much guessing here, but I think the details of any NDA's could be kept confidential form shareholders, I would not even think the name of the counterparties would have to be disclosed, perhaps only that a certain number actually exist; however, at that point, the company and its directors have a fiduciary duty to recommend acceptance or rejection.  If it can be shown later that directors/management persuaded shareholders to accept an offer that could be shown to be too low, I think they'd have recourse against them and the company.  (And, now, the larger, acquiring company would be on the hook, since they would acquire all assets and liabilities of POET.