The way the schema has been written, if an archive page was ever added, any thread which has ever been featured will automatically be listed there.
However, be aware that the original thread title and content would be used, rather than the featured title and content, as once a thread is unfeatured, the data is removed from the featured table.
I doubt this is an issue for most, if not all, as in the vast majority of cases the content will be the same, with just small changes made to improve the layout of the featured thread, etc.
Sounds perfect for our use case assuming the URL remains the same (for SEO purposes).