Future expansions.

Well, the moon and star are essentially a symbol of Islam. If nothing changes in the Academy's culture, it will likely remain that way. Besides, only the Sylvan and the Dungeon, as well as the Fortress, have decent symbols – they are in the form of a dragon. These don't really suit as faction symbols, and that's why I'd say there's only a 10% chance that they will remain the same after the release of the second expansion pack.