I'm a Realtor and parent in Ann Arbor. Ann Arbor is a "school of choice" community, meaning, if your you want your child to go to Skyline and there's a spot already, he/she is in. If you child was already attending and you move, there's a spot for them and they can stay, this has been my experience here. Best to call your school but they try not to rip a child out of a school they have already been attending just because they move. You will need to find a way to get them there, the bus system will not deviate from it's assigned path, but it might be as easy as taking him/her to an already assigned pick up spot on your way to work.
I hope that helps. If you need any more help or have more concerns, I'm here to help.