Currently you can filter the Timeline view by Feature status but the Release status is more important to our planning since we use the Release Status to communicate with Execs. I can do it by selecting all releases then removing the ones that don't fit my criteria but automation would be better.
This can be achieved on the Reports -> Timelines page from the example report, "Releases by product with status." More on creating timelines.
I likewise have emailed support about this. We plan on adding quarterly releases going out a couple years, initially populated with little more than themes. As we get closer (1 quarter out) those will be replaced by true releases loaded with actual features.
The current view means we need to go in and update every time we add a new release.
FWIW I get ALMOST what I want on the Portfolio view, however I have no filtering and no ability to control the layout (and it comes right now with almost no detail, just dots w/ dates)