Well, to put a 320 guy on the 330 is about saving money and time. Differences course will take hoy long? A couple of weeks?
Putting a 737 or 757 guy on the 777 means a new TR so, time and money should be the same as moving there a CRJ or MD pilot.
It makes sense to give priority to the bus guys but in the future I don't think they will give priority to a Boeing guy in front of, let's say, a CRJ pilot.
Anyway, all of this is just opinions or "maybes". Never know.