Published discussion on diagrams
A separate discussion is implemented for published diagrams (and later other artifacts). Unlike the discussion for elements in the repository, it is not linked to Enterprise Architect (because EA does not know anything like a published diagram, in the sense of a publishing module. And of course, the moment a user comments on a published diagram, it may no longer even exist in the Enterprise Architect repository (it is only in the publishing module) or it may have been significantly changed and the comments may no longer be relevant.
In addition, if one diagram is published for different groups of users (for example, suppliers) and these groups are not supposed to see each other (their models), it is more convenient if the discussion is separate.