We have an Outlook folder that is created by EVPM. We want to rename that folder.
Can that be made retroactive so it renames the previously created folders and not just new ones?
Rob is right: it will not rename the folder, just create a new one with the new name, right alongside the old one.
The best way to achieve what you want, in my opinion, is to rename the folder in all existing mailboxes using an EWS Managed API script (here's a decent example of how to do that) and then implement the folder for new users by updating the name in the EVPM .ini file.
You might also want to take a look at the Retention Folders feature that was introduced into EV 12.2's Retention Plans. It can do a lot of what EVPM can and is much easier to use.