Yeah. I really like this idea of warning the user. Keep the usability without losing the functionality. Also, not sure if anyone is thinking of this, but there

Yeah. I really like this idea of warning the user. Keep the usability without losing the functionality. Also, not sure if anyone is thinking of this, but there are security concerns if you were to serve up old pages on a new domain. If that old page has a vulnerability, it now has access to data in the new domain. This is more for archiving, so the old pages wont get patched.