These release notes for Cumulocity IoT release 10.15.0 include information on all relevant changes (new features, improvements, and fixes) that have been implemented in Cumulocity IoT Core, Cumulocity IoT Streaming Analytics, Cumulocity IoT Egde, Cumulocity IoT DataHub, and Cumulocity IoT Machine Learning since the previous GA release.
Moreover it includes announcements for planned and implemented deprecations that might require action on your side at some time.
You can find the corresponding product documentation for release 10.15.0 at https://cumulocity.com/guides/10.15.0/welcome/intro-documentation.
The Operations release notes for the Cumulocity IoT platform are not publicly available. They are provided on the Software AG Empower Portal (credentials required).