@notify-ing post authors is actively discouraged, and adding all editors would introduce complexity for an uncommon use case, it's unlikely that the tab completion will be expanded to include those options. Note however that the tab completion will already include the post author in the list of names in cases where that user has commented on the post, and there is at least one other comment posted by a third user.
That said, completion of the most recent editor and moderator responsible for a close vote wouldn't be too difficult to implement with something like the following, based on the minified code:
var t = o.closest("#question, .answer")
.find(".post-signature .user-details a[href^='/users/']");
var s = l(t.last().attr('href'));
var editor = t.first();
var moderator = o.closest('#question').
.next('.question-status').find('a:last + .mod-flair').prev('a');
o.find("a.comment-user").add(editor).add(moderator).each( // ...
(Note: the existing code takes care of the "is not me, is not post author" issues later)
Still, since these aren't very common usages of
@notify-cation (and there's a bit of an edge case with finding the closing moderator), I could see why the lack of a compelling reason to add them would keep it from happening.