To me, if someone wants a DADT policy, then chances are they haven't fully embraced the true meaning of Polyamory, and they definitely have not learned diddly squat about Compersion!
And to me...I just don't want that at all. I want to know what my partners are up to and I want to share their happiness about it. Tell me the juicy details and maybe it'll even give us new ideas on what we two can do together. What's to hide? It's completely against some of the big major points of being poly to begin with!