I think that you need to allow us to still go up in old ranks (who wants to permanently be a wood serf?) but only for completing a number of quests. That way people that upset because they are low rank and wanted to be a higher one are are happy, and people can't go up in rank by posting comments everywhere.
The current ranking system has already been removed, even from posts as you may notice. So someone could only tell your old rank by checking your completed Quests.