This will be addressed after early access launch. Shawn has shared in his streams that they've been discussing class quests. Possibly they will continue up to 60, for every class, with some sort of epic/lego reward. I'm excited to see what they do with the class questline(s) and hoping they give us choice branches at higher levels. Meaning, do this task for npc A or do this task for npc B. Each quest path having a different reward.