Not necessarily. In my experience, the disconnect works in one direction. In other words, you should get any disconnected FPs before any connected one. Getting CS before RSR would work fine but not RSR then CS. In the second case, normal connected rules apply. At least that's how I remember it working at WDW before FP+.
That's interesting, never knew that. Thanks for sharing. If Screamin' is still disconnected we'll have to factor this into any FP plans. We'll be back in a week and the kid just hit 48" - so we're riding (and riding, and riding, and riding....) Screamin' a lot.