A shot from one of the trailers reveals the moment that Yavin 4 Base decide to go to war at scarif.
This would seem to be Bail Organa there making a speech as well as Doldonna and no doubt would feature R2-D2 C3-PO and Leia possibly abandoning or at least putting on the back burner their mission to tattooine.
UGH, I would LOVE that scene.