Character arcs
This probably should have occurred to me earlier (of course, I also heard it late enough that I didn't give poor Rachel any (deserved) spots on my year-end lists), but parts of Come And Get It really do sound like the necessary prelude to "Since U Been Gone" (particularly "All About Me"), the moment of doubt and loneliness and weakness that comes before tossing the jerk out on his ass. Or maybe the moment after, when you don't change your mind (because he is a jerk, and she is better off without him), but the hurt starts to be felt (especially, say, "Nothing Good About This Goodbye").
