Hi @HeatherBeatty ,
I don't believe there is currently an option for something like "read only for x years then remove all access". There is an end date (which can very by user role, or even individual enrollments), and a switch that controls whether users can see the course in read-only mode after the end date or not. Your institution/school could have scripts or SIS processes that completely delete a course after another amount of time, which could actually work out somewhat like you're describing, but someone would need to write scripts or configure your SIS integration to do that.
-Chris