The "view this in your browser" link was always personalized for tracking, not semantic, IIRC. It did include the actual content of "Hello, {first name} {last name}!" tags, which obviously wouldn't work here for every unique reader.
How long does this stick around? As long as you have a MailChimp account?
I guess I assumed that the URL was unique per-user and would be deleted after 30 days, because the primary use case of Mailchimp seems to be not-quite-spam "We're having a sale!" bulk campaigns.
