DISAPALOOZA is a private event, hence it has nothing to do with regular park hours or park guests. If you are in the park during the day as a regular park guest then you will have to leave the park just like any other guest and then return for the private event. As suggested by a PP, this may be a good time to relax at CityWalk and grab dinner/drinks before the event.. The DIS team will likely release more details as the event gets closer with details on exactly how to enter the event, where to line up, etc...