Copyright is probably appropriate because it was the last time the page was majorly updated. We do not change copyright dates unless that happens as doing so would imply we had new content which needed a newer copyright. Since copyright lasts at least 50->75 years around the world, it means the documents are protected until 2065 at least.

The feed looks like it is working as of 2018-06-19 14:00 UTC

@smooge is right. Closing.