I think they may apply it at some point going forward but to be honest it accomplishes very little in the older worlds so why bother. I can't imagine many people are using multiple accounts to farm, that seems an early server issue not a late server issue.
As for the subs I think it was wise to not implement that. Think about it, if you've had a sub that you invested years in developing in one of those old worlds how angry are you going to be if it is taken away from you to solve a problem that doesn't exist really in those old worlds?