Paramount anticipates its merger with Warner Bros. Discovery will close in September – but members of the entertainment community, including leaders in the documentary field, are saying, “Not so fast.” An open letter protesting the merger has attracted more than 4,700 signatures to date, with marquee names attached that range from J.J. Abrams to Adam McKay, Kristen Stewart, Sandra Hüller, Robert De Niro, Sofia Coppola, film distributor Richard Lorber, Pedro Pascal, Ramy Youssef and more. Among the prominent signatories from the doc space are Alex Gibney, Laura Poitras, Abigail Disney, Yoruba Richen, Laura Nix, Lucy Walker and many others. On the new edition of Deadline’s Doc Talk podcast, we talk with two highly respected figures in documentary who also signed the letter: filmmaker Marjan Safinia and Lois Vossen, founding executive producer of Independent Lens .…