You can add a dependency link between releases, but they don't show on the release roadmap. I'm talking about the arrows between phases that you can add within a release - enable showing an arrow between two releases.
|Release time frame|
We just gave the Gantt chart a major upgrade. Get ready for a fresh look, smoother experience, new master features view, and more.
This new experience will now show the dependency links between releases shown on the Gantt chart.