Yes this was a joint development project and the movements are identical except for two trivial differences. For the alarm on/off indication Blancpain uses a hand; Breguet has a small disk turn. For the 24 hour home time indication, Blancpain now uses a large centrally mounted hand that reads out on the outside of the chapter ring; Breguet uses a subdial (which is what Blancpain formerly did). That's the sum of the differences. (I guess if you want to be picky you could mention the new Marine Reveil that uses the same movement but leaves off the second time zone indication--but let's not deal with every little detail like that).
Jeff