We only use Master Features for a select set of Features, some features stand on their own. Without looking closely at the release notes, I had assumed this was the case. We can't use the Master Features (or it's not really useful) if we can't view them on the same screens (Feature Board) as Features. It's not worth our time to make a master feature container for all our standalone features just to accomplish this.
I would expect a Master Feature view to rollup all features in a given release by Master Feature, and those individual features be hidden, and then features without a master feature to continue showing.
If a master feature has features in several releases, then either show it in the final release only, or preferably, show it in every release it has component features in (rolling up and hiding the individuals).
I'm voting for this because I think Kaitlyn has a point, although, for me, it may be a little too early to tell. Already, I've seen some challenges with transparency across features vs master features. I'm curious to see how it plays out.