@Sinduskhas a very valid point. That sense of new and unspoiled adventure is a very appealing thing. So much so that it even manages to draw off longtime players to start over with no skills and all their possessions gone just to experience it again.
In my opinion, that is perfectly fine and well. It generates money and it brings a level of freshness to the game that can get very stale in a lot of aspects over time.
All that being said, I wholeheartedly agree with @Revnikthat we have to then deal with the natural waste products of this process, which are several old, stale, heavily colonized (ruined) servers with active player counts in the single digits.
The way I see this process being closed looped and self sustaining is to accept travel of veterans to new lands as a normal expected part of the process and regulate it in a way that is beneficial to everyone. I do not mean totally wide open as in letting veterans travel to harmony on day 1 that it opened, but there is no reason a timeline can't be established saying for example:
New Server 1 implemented Jan 1st
Free travel to NS1 opens July 1st
Oldest Server 1 closes December 31st
The general idea is just to introduce a constantly rotating cycle of adding a new, fresh server to the start of the queue and then some specific and highly advertised time later you remove the oldest server from existence.
The timeline may need to be adjusted for PvP servers as there are fewer of them and they seem to go through cycles of change in playerbase and leadership more often than PvE servers by far, but as far as PvE goes, with the current number of servers we have now (including NFI) we would have a total lifetime for each server that is over a decade before the server is wiped. I think that is more than fair to give people who are averse to moving a chance to enjoy a long settled life on a server before it is discontinued, and it gives those with more sense of adventure a new server to explore/conquer every year (if using my example timeline).
As for the impact of veterans on a new and fledgeling economy, I feel as though this impact will start to average out and become more mild after a few rotations of servers being created/destroyed, but I cannot be certain.
If someone takes a hiatus and loses things, they didn't care enough about them to check on them in a 12 month to 10 year period and it moves all of that crap out of the way for new and excited players to use that space in their stead. We've had many conversations in the past about the fact that old abandoned crap stays to clutter up the servers and get in every active player's way for FAR too long. Example: I had a friend quit the game about a year ago. Still to this day I see his caravel parked out in the middle of the ocean in the exact spot that he logged out in. Judging from the damage currently on it, it will occupy that spot for at least another 2 years, serving as both an eyesore and another reminder that this land was well and truly spoiled long before you ever got here (for new players).
Thank you for coming to my Ted Talk...