There is no reason for them to run much past 2am. The bars at Pleasure Island do their last show about 12:30 am, then last call for alcohol is about 1am. Then about 1:30, the clubs close and usher you towards the street. Then about 1:45 PI Security starts ushering folks towards parking and the bus stops. So usually by about 2:10 am, PI is clear, so by 2:20, 2:30 at the latest is when the last couple of buses run to get everyone back to Disney resorts.
Why would you need a bus from PI after 3am???