Not technically sure which released version it affects, but it's on our currnet testctools candidate.
Schedule calls it "New Event" and Assignments calls it "New Assignment" but it's "Add" in Announcements. I thought I understand that it was supposed to be Add alwaays. And only add the object in tools like Resouces and Discussions where you can add more than one different object (folder/item, category/topic/response).
Seems like Schedule and Assignments should go the way of Announcements and just say Add.