I know this is incredibly "hacky", and not ideal, but I found a way to prevent the unsubscribe message from displaying at the bottom of responses (at least visibly)
Just put this at the end if the notification. It uses your <div> but also sets the link and font colors to white so you can't see them in the email and changes the font size to 1 so it is now microscopic white text when replying.
Like I said, not ideal, but best I can come up with until they a feature added to exclude it.
<head>
<style type="text/css">
.div A:link {text-decoration: none; color: white;}
.div A:visited {text-decoration: none; color: white;}
.div A:active {text-decoration: none; color: white; }
.div A:hover {text-decoration: none; color: white;}
</style>
</head>
<div class="div" style="display:none; font-size:1; color:white;">
