Currently, the Release Roadmap page is sorted by date - with older releases shown at the top and newer releases shown at the bottom - which allows the roadmap to be shown in a time based manner.
While we understand your use case, one workaround would be to leverage the filters and save/share views based on the release blocks of interest. Based on current priorities, we are unlikely to make changes in this area in the near-term.
And how can I reorder my products? It seems that when you create a product it's positioned as static and you can't reorder amongst other products... very limited and not flexible!