The 4 will only apply to MK.
From touring plans.com
Our "crowd level" estimate is based on a scale from 1 to 10, with 1 being least crowded conditions and 10 being most crowded. The scale measures the peak wait time at the Magic Kingdom's three headliner attractions (Space Mountain, Splash Mountain, and Big Thunder Mountain Railroad). Thus, the Crowd Level is a "worst case" scenario, predicting the longest wait at any of these three attractions on a particular day. Predictions for parks other than the Magic Kingdom are an approximation