Hi @SusanDarlington
Just to clarify, do instructors re-use course shells in your Canvas instance, or do you create new course shells each term?
When we first started integrating with our SIS (way too many years ago to count!...), we made the choice to create new course shells for each section, and for each term in which the course was taught. There was some concern about the number of course shells that resulted, but it has vastly simplified our processes to have new shells created every term.
Of course, even if you create new course shells every term, it is possible that an instructor will be assigned to a course, copy their course materials into the new course, and then the course will be re-assigned to a different instructor before the term actually starts. (Faculty assignments changing in the middle of the term is a whole different issue...)
In our case, that does not happen often enough to be a concern, and instructors are generally aware of what's going on if they are replacing another faculty member in a course, but if it were a major issue for your faculty, you might look at limiting the window that instructors have to copy materials into their courses, or how far in advance you add instructors to courses in the new term.