Hi, Brian. So, we want to determine this via the API because we're developing at LTI tool that lets instructors create users in our instance of Canvas. The tool seems to silently fail if the course is closed/no longer in a state where users can be added via the People tool.
(Why are we developing this tool? Here at the U of Michigan, users authenticate to Canvas with their UMICH password -- but we have a pre-existing system that lets people *without* UMICH email addresses set a password to get access to certain UMICh resources. In some cases, instructors want to let someone w/o a UMICh address into their Canvas course but can't because they have no underlying Canvas account.)