I am wondering if maybe Patrick Doyle decided it was safer to clear his schedule for the coronation commission rather than risk having a clash trying to finish a movie score. He's been doing lots of media work so, while it may not have taken him long to write a 4 minute processional, the associated obligations behind the scenes might be considerably more than we might suppose at face value. I'd be astonished if PD and KB have fallen out.
Y claro...
Has anyone tried to contact either Branagh, or Doyle, to ascertain why?