I think Clovis West's destination depends on two things:
1) The relative strength of the NorCal and SoCal Opens. If there are more (numerically) deserving SoCal teams than NorCal teams, CW could be shifted north so a team like Fairfax, say, could go Open, thus giving the LA Section an entry.
Along that line, it could also be seen as a way of balancing the two regions so that it's just as difficult, in the committee's eyes, to get to the title game from the North as from the South.
2) Politics, which does play a role in almost everything, but usually in girls' basketball to a much lesser degree than in boys. Still, it could be that the Southern Section and SoCal in general is looking to maximize its chances of winning the Open, so moving CW north would eliminate one of the two primary contenders before the final game.
On the flip side, moving CW north would drop a team from the NorCal Open that might well have a chance to win its divisional title (Cardinal Newman would be the prime example, I'd think).