For the future updates and replay-ability. Make it like poe with seasons, a new server for every new major update and then it merges back into the main server for the next season which always is fresh or people can choose to just continue the season on the main server on their already 60 as that also should then be updated.
Implementing this might be hard, idk but youre blizzard so i expect you to be capable.
This will always give a fresh economy and i think it would be fun af. Do a season battlepass or something for the updates or youre locked to the main server only for free?
This will also give an oppertunity to correct what people didnt like as its merged for the next season. Opens a lot of windows and oppertunities.
Im also interested what other people will think?