I think they are expecting huge crowds during that time. It will be interesting to see if this happens or not. So far DL doesn't sound like its packed except at SWGE, but WDW has an entirely different population with fewer locals making up the majoritiy of the crowd.
Not sure if I'm excited about the parks opening that early or not. The extra time will be nice, but I'm afraid if you don't get there early (within an hour of EMH start time ), the parks may be packed.