Is honors band a wind ensemble? If so, the saxophone parts are rarely of great consequence, so alto and tenor play a similar role. As for a demotion, they probably just needed another tenor in the instrumentation. Between the two horns, the difference is pretty easy to get a grasp of. The fingerings are all the same in the range he will be playing, and the concept of the instrument is pretty much the same. The only real diffference in such a case is that the tenor is heavier.