One of the things to note is that it is not the death of Google Plus, but rather death of Google Plus for consumers. It is uncertain what this will look like. Surely they will allow users outside of the domain, but I am not sure how this will all play out.
Reading this update from a few months ago about the ability to add a Google Group to a community:
We’re adding the ability to directly add users and Google Groups as members of Google+ Communities. When a moderator adds a group, group members are automatically added to the community. Subsequent updates to the group membership are automatically reflected in the community membership.
I wonder then if the workflow will involve a process of adding people to a group and subseqeuntly to the community? If this is the case, it maybe possible to use Plus for CLMOOC (and any other project) as long as the community is housed in a particular instance of Google for Work.
Personally, I think that Plus has had its day, but if it works within the context in question then I still reckon there would be options moving forward.