Consider adding a small icon to indicate whether the article is featured or not.
Topic on Talk:Page Previews
That's an interesting idea. I've created a task to start a discussion with the engineers.
Related discussion "What metadata should be displayed (article quality, last edited, user views, settings icon etc.)?" - https://www.mediawiki.org/wiki/Topic:Tg8m178nj6doq7k3. Relevant discussions are often better linked together.