There are changes being imposed on Flight Operations from above, with planned expansion and shortage of crew CCQ on the Boeing & the Airbus fleets is the obvious way to go. Many of their Middle East competitors utilize CCQ and Saudia higher management are asking " why should Saudia be any different? In the past it was Saudia Flight Operations that were reluctant, mainly because of vested reasons within the Flight Operations Management community.
The plans for the A330R is mainly to operate regional and some higher capacity domestic routes. The regional routes are basically anywhere within about 3 hours flight time-North Africa, Near & Middle East, The Persian Gulf, India, Pakistan, some East Africa, etc. The longer range A330's might pick up a few routes into Europe but that is not really the plan. The A330 is the most likely fleet to have a decent and proper commuting roster, for those that want it.
The above is my best guess.