No, if you disable a user for archiving, it will not restore the items to exchange, it simply won't archive more things into Enterprise Vault from this user.
My suggestion:
Try to do a "Former Employee" Provisioning Group & Policies
Then, depending on your needs, do the following:
-> Let it delete all shortcuts in the user's mailbox
-> Then you can export 2 PST Files, one from the active mailbox, and one from the Archive
-> Then you can delete the mailbox & archive
OR
-> Set the Policy to archive everything
-> Then delete the mailbox
-> and leave the archive in place
Cheers