After about 7 days of playtime your 'Returner' status will drop off.
If, at this time, you otherwise qualify for the 'New Adventurer' it'll be applied. New adventurers are anyone who hasn't completed the 2.x main storyline as well as have over 168 hours of /playtime. So if you don't have these two flags cleared you'll continue to be a New Adventurer until you do. Well unless you just disable your status manually.