The feature board shows a column for each release, but unless you name the releases to be identifiable (I use release versions), then it's hard to quickly see the theme of each release. It would be good to have the option of displaying the release them under or next to the release name. Themes can be long, but it would still be useful to be able to see just the first few words that would fit (and perhaps you could see the whole text on hover).
|Release time frame|
The feature board currently contains the release name, and is heavily focused around the Features at hand. As you described, it is possible to name the Release with the theme in mind, but this may be difficult for longer themes. Its also possible to click on the release name to get more information.
The Features roadmap screen provides the ability to show Themes on this page, as this is meant to help with sharing roadmaps with key stakeholders.
Because of the additional areas where this information is accessible, along with current priorities, we are unlikely to make changes in this area. I hope you can understand.