1. Diana was already out of their lives. From the moment of the separation, she was out of there.
Well, they would have attracted media attention which wouldn't have been focused on her.
2. In point of fact, they like Camilla. She paid (and pays, I assume) attention to them. They said all the right things about missing their mother, but it was notable that they rarely referred to her by name.
3. Charles, stepping away from his duty for love? He might be offered that, but he would have turned the offer down before it was finished being made.
Anyone who knows Charles would know that duty comes first. He certainly wouldn't repeat Edward VIII territory.
4. Diana, warning someone? That's an interesting concept.
I confess I don't have an objective viewpoint here, what with mainly having seen things from the Charles viewpoint. But there was a reason the staff and underlings around the place despised Diana.