In Ohio the main reason a course is replaced is that the race organization has a desire to change the route. It's rare for me to see a course be replaced because of physical changes to the certified course. Maybe they do change, but if no one tells me I don't know.
The main reason for replacement is tidiness of the course list. If replacement is conscientiously done by measurer and certifier, only one course with a given name is active.
In other words, a replaced course is probably just fine, and could be renewed without any problem.
What if "replacement" was not an option? What would we lose? Isn't the latest version of a course generally the active one? Is "replacement" just an exercise in bookkeeping?