Great idea.
Need something close to that, since a workflow can be a powerfull tool to manage absent contacts.
Let’s say a contact does does not visit a page, or click a email for 30 weeks. I can send them an email to tell them that “we miss them” but we need to know if they are still interested. If they don’t click the email to be re-engaged, then the contacts could be deleted.
Doing something close to this, but with a manual action in the middle. Because the workflow never deletes contacts. Only removes them from lists.