I had some time recently, and the idea struck me, so I put together a basic plugin that redirects /latest/ to my site’s latest post. Try it out:
Called ETH Redirect to Latest Post, the plugin is on WordPress.org now, as well as GitHub and my GitLab instance.
The plugin is ready for latest to be translated, but more importantly, it adds a field to your site’s Permalinks screen where you can set the slug.
Strangely, I couldn’t find a Core ticket for such a feature, and nothing turned up in the plugins repository, either.