Hmmm... where is the interview that address the DoH/DoL ranking system? This is the first I've heard about it.

Y: Diadem's exploration progressed as players did their work, so we are going to rebalance the whole island. The basic image is "Go to diadem and gather mats, use that to craft and repeat this to restore Ishgard". (Talks about the ranking we found out about in the other interview). Some players might feel cramped if we provoke too much competition, but we also think competing is a part of gaming, so we'd like to challenge what we haven't done before and hope to find something new by using that as experience.
Q. Why are you splitting them into seasons?
Y: To avoid the same person from dominating the top ranks. If we have a rule where you can't reobtain a prize, it will provide space for others to work hard. (Note: talks about info we know for a while). We will continue to update the content and expand on its size.