I have never seen them perform a sweep of the ENTIRE park prior to HHN. You may be required to hang out in a roped-off area and wear a wrist band, but then you are allowed to go right back into the park before the mob is generally allowed through the gate. This has been the standard, but anything can change. In my opinion, there isn't really much reason to clear the entire park of HHN passholders and Guest Svc. may not have completely explained the procedure.