If Scholar does play in the same manner as it's XI counterpart, I don't think we'll actually be seeing light arts/dark arts in the same sense as XI but rather the arts of enhancing and enfeebling.

It would be interesting if the SCH abilities serve as a dual purpose where each one is effected by whether you have Light art or Dark art active. While light art is active the abilities you use become enhancements which support the party, but when you switch into dark arts, the abilities you used as enhancements now turn into enfeebles which you use on foes. Would definitely give SCH an interesting dynamic of how they present themselves switching back and forth between the two stances.