Gradebook activity item names are not updated on ajax name change of activity link in the course section. For instance, create a quiz, save and return to course. Then change the quiz name by ajax name editing. Go to the gradebook and the quiz grade item name is has not changed to the new one, which suggests that the ajax name editing doesn't trigger grade item update. The grade item name can be updated only by editing the activity settings, changing something and saving, which of course somewhat defeats the purpose of the quick name editing.