You are strongly advised against reusing a local workspace that was created with a previous version of the product. However, running a new migration from Pacbase is not necessary.
You are advised to start from an empty local workspace and to load the content of the repository workspace into it. You can reuse the repository workspace that was used before. The metadata will then be correctly reset for Rational Programming Patterns and its required products.
Even if it is strongly unadvisable, reusing a local workspace remains possible. If updating the local workspace is required in a new Rational Programming Patterns version, then a migration process for the existing local workspace will be provided as far as possible. This process might be simple, that is to say an individual migration upon the opening of an editor, or the migration of an entire workspace in a command-line mode. In any case, this process will be documented with the version.
For example, for Rational Programming Patterns V9.1.2, if you must reuse a workspace from the V9.1.1 version, then the Text and Meta Entity instances of the Pacbase facet will be migrated when the editor is opened. You will then be able to update them.