You can search the flight number to determine if it originates somewhere else and continues to MCO through your airport. There's no way to tell if there will be connecting passengers, but if your airport has a fair number of SWA flights and you aren't going out on a very early morning flight, there's a decent chance there will be at least a few. If you are flying out of someplace like Chicago-Midway or BWI, you can bet there will be a LOT.
Just for fun, here's the order of who could be on the plane if there's something of everything going on:
- Passengers continuing on the same flight who started from a different airport before stopping at your airport
- Medical preboards
- Business Select ticket holders
- Passengers who used EBCI that are connecting to your flight from another flight into your airport
- Passengers who used EBCI and are starting their travel at your airport
- Passengers who checked in 24 hours before their original departer andare connecting to your flight from another flight into your airport
- Passengers who checked in at 24 hours and are starting their travel at your airport
- Everybody else
A-List frequent flyers get boarded somewhere in the mix of 3-5 above, but I'm never sure exactly where.