I'm sure they will try to accommodate them by having a Pac12 team be in it when possible, but with the expanding playoff I just don't see how it would be possible to keep the old traditions. Maybe if they cut out the G5 entirely and basically moved us down to Div II, you could have an 8 team playoff and their 5 champions can keep their traditional bowl tie ins.
I think we have to look at it as a new era and the things that worked before don't anymore. I think we all would pick the expanded playoff over what we've had, even if we are sad to see those traditions go away.
I remember way back in the 1990s when the rumblings of a "playoff" were discussed, the idea I most often heard was let the Bowls as they were then constituted be played with all the various tie ins, and then whoever came out of that 1 and 2 would play a week later for it all. The main objection at the time was that it might be unfair if say the Rose Bowl featured 1 vs 2 if say Michigan and USC filled those spots and then a #3 Notre Dame played #17 Nebraska in the Orange Bowl...with the thought that ND would have had a much easier route to a title game.
Still though, that could have been pretty good too.