It would be nice if worlds and world names are tied but are separate things. So if a world decays, only the name decays and is freed but the world itself is still in ownership of the previous user. the guy who finds it can create a new world with the name and the decayed world get a subject name or something like that. I dont know if it was possible before, but we need a view of all worlds where a user has locks placed in for this to work well. And to prevent abuse the world name should have a history with links to all worlds this name was previously connected to.
This would allow for shorter decay times as well, so it would be fine to have a wl decy in less than a year imo.