Can these posts be automatically deleted considering a page of "I put you on ignore." isn't notable or relevant content?
Coming from Atlas, I don't think this complaint is really about "I put you on ignore" diluting relevant content. Atlas has an extensive history of creating irrelevant threads and leading off-topic tangents in other peoples' threads.
I suspect that the real reason Atlas has made this request is because he's disheartened that so many people are ignoring him, and wants to feel like he can still influence the people who are ignoring him.
I agree that posts which have no other content than declaring "I'm ignoring you" are a waste of space on this forum. People should only post relevant comments/information in threads, and if its irrelevant to the topic at hand, moderators should move or remove it. However, I don't think "you're ignored" posts need a special moderation policy - irrelevant is irrelevant.