Best Practice for replacing courses in learning plans

Summary

We are getting ready to roll out new versions of several courses. Some of the old course versions appear in learning plans.

Content

We are getting ready to roll out new versions of several courses.  Some of the old course versions appear in learning plans.  What would be the best practice for this.  Keep the original version in the learning plan and add the new version?  Replace the old course with the new version and let everyone know they need to finish the new version to complete the learning plan (again)?  Or start with a fresh learning plan.  Something we will be doing as we move from the old learning plan DO to the new widget.  Still wondering the best way to transition every