Hi Tam,
As having had to do something similar recently, I would like to share my experience.
I would recommend setting up new Knowledge Bases, and moving the articles in as required and I would also recommend creating new categories as opposed to renaming existing ones.
Knowledge Categories exist on the knowledge base level, so will always have a "Parent" of the Knowledge Base they are associated to. These can be renamed and you can move existing Categories over to new knowledge bases, but to avoid confusion I think it is best to start the categories from scratch on the new Knowledge Base.
If you were to rename the Knowledge Base, the process of moving/renaming Categories could get very hard to manage. As the categories will still exist on the same "Parent" level you will only be renaming the categories for Published articles. Outdated versions will show the old Category name, and it could get confusing then for Authors when selecting a Category. By adding new categories to a new Knowledge Base, it removes the risk of the old categories showing up.
Versioning should not have an impact, as previous versions of the articles will still display the old category. This can be useful from an auditing or record retention standpoint, as you can always go back and see how many articles were moved over, or what category they used to be a part of.
So in summary I would recommend creating new Knowledge Bases and new Categories as required, and marking the old ones as Inactive once completed moving everything over.
Regards,
