Hey Jason, I looked into this. RPS publishes around 9 stories a day, so unread stories can pile up quickly across your 30-day unread window. What you’re seeing is likely a backlog of stories from the past few weeks that hadn’t been marked as read yet, not old stories being republished.
If you’re seeing something different from that (like stories from months or years ago), let me know and I’ll dig further. Just give me hints about what you read and what’s coming back.