In the Features roadmap, the info of "Not shown in notebook" really clutters the view and doesn't add any relevant info.
I also am having a hard time understanding what it is that triggers a feature to not be shown in a notebook.
Regardless, I don't want to see that line, especially if there aren't any items that are not shown in a notebook - in that case, this is truly useless information and only serves to needlessly complicate the visual impact of the roadmap.
Each feature has a checkbox on the Features roadmap to indicate whether it should be shown in a Notebook. Including this information allows users to choose their releases and easily decide whether or not features should be visible. With this in mind, this current behavior is by design.
While we understand that it may clutter the view in the application, the primary intent for the page is to create exportable views.
This is a great feature, but I think the better solution would be that if there are zero features not shown to hide this line as it does retract from the roadmap and adds unnecessary cognitive load. Also, most importantly, it insights mistrust with customers/stakeholders that you you are "hiding" features.