If I am accepted to the Magnet or IB Program and decide to drop out, do I have to return to my sending district?

Possibly.  School Choice seats are only available for the advertised program.  If you drop out of the Magnet or IB Program, and there are no Choice seats available in your current grade level, you will be required to return to your resident district. If a Choice seat is available, you may be able to apply for it, depending on the time of year you withdraw from Magnet or IB.