Today when we use the Features board view, the view displays Features under Releases horizontally. This means that as a workspace is used for a long period of time, or as we ship many Releases, that this is a long scrolling horizontal list. If you filter by Release Status today, it merely hides Features that are associated with Releases that do not meet that filter criteria - BUT it leaves the Releases themselves still visible.
This is a frustrating piece of UX. If I ship something, and then I say that I only want the stuff that needs management for future releases, why would I want to see releases that have already shipped?