Incorrect Behaviour of Preferred World Status

[Niwashi]

In the case of newly created characters, these bonuses will continue for 90 days (including the day of creation) regardless of any change in World status."

That sentence points out twice ("newly created characters" and "including the day of creation") that it's based on creation, and nowhere suggests that it gets reset back to zero when the world status changes. It's doing exactly what it says. It's just saying you'll still get your full 90 days regardless of any changes to the world after you've started.