Deadline is reporting that The Post is already set to begin production this May, with a potential late 2017 release. Holy crap! We just found out about this Monday and it may start shooting in like six weeks. It's understandable that the way this picture may capture the zeitgeist that getting it out as soon as possible could be vital to the film's popularity and overall success. Director Steven Spielberg will be on a tight schedule to get this wrapped in time for screenings at fall festivals.
If any film were going to be fairly straightforward in regard to shooting, however, it's this one. Most of the scenes consist of dialogue in interior settings. No special effects. No large, sweeping landscapes. I imagine additional casting news will likely be forthcoming as well.
This would leave the fall open for Meryl to shoot The Nix, which I imagine they'd want to release sometime next spring to most effectively contend for Emmy nominations.