I had some Hubs that weren't featured for a while but I updated them, added new capsules, deleted old pictures and added new ones.
I even had one Hub, rewritten almost completely because it was absolutely low quality content. One of my first it was and the changes helped my Hub into getting featured again.
It keeps us Hubbers aware of our older Hubs to update them or delete them if it's not worth pimping them at all. Good luck!