I think it's because they've locked down certain areas of the park prior to 5 PM to make it so guests are forced to take certain paths, but not positive yet. Additionally, the NY S&S at least already had us in an organized line before I even got there at 4:30 so it was very easy for them to just open the barricades and lead us over to the Halloween queue in an organized fashion when they got the all clear for the crowd sweep of that section of the park.