"Dolphin has seen constant updates, with new features and enhancements coming side by side with bug fixes and stability improvements. " <-- yes that is what I call rolling release.
"All of this was achieved without a new release." <-- No. You were doing release. Just not changing major version numbers.
> These are proper release builds however, with the full infrastructure and support that comes with them. They are tagged as releases in Git, allowing our distribution partners to properly support us and our users.