Once you find out if those topics are required by the state find out how the state determines whether or not a student has covered those topics. Often times items are in the state curriculum and therefore required, but if a student were to move to the state after that year, they too would be missing those topics and would not be required to go back a year to make them up. If there is an end of course state exam, then ask that DS be allowed to take the test this year as a way to test out of the class for next year.
If you call the state dept. of ed. they will be able to tell you what is legal to do in the state, as well as give you advice as to how to meet the requirements in different ways than the traditional. (At least that is what we were able to find when we called the state and talked to people in the gifted ed. section.)
Many states do not actually count middle school courses as being requirements for graduation. It is only the high school courses that are required, and the timing of those are usually up to the individual school district to determine.