Highlights include:

• Built Cesium.js is no longer AMD format. This may or may not be a breaking change depending on how you use Cesium in your app. See our blog post for the full details. https://github.com/CesiumGS/cesium/pull/10399
• Model.boundingSphere now returns the bounding sphere in ECEF coordinates instead of the local coordinate system. https://github.com/CesiumGS/cesium/pull/10589
• Models and tilesets that use the CESIUM_primitive_outline extension can now toggle outlines at runtime with the showOutline property. https://github.com/CesiumGS/cesium/pull/10506
• Added support for point cloud styling for tilesets loaded with ModelExperimental. https://github.com/CesiumGS/cesium/pull/10569
• Fixed a crash in the 3D Tiles Formats sandcastle when loading draco-compressed point clouds with ModelExperimental. https://github.com/CesiumGS/cesium/pull/10521
• Fixed crash when loading glTF models with the EXT_mesh_features and EXT_structural_metadata extensions without channels property. https://github.com/CesiumGS/cesium/pull/10511
• Fixed a crash in the 3D Tiles Feature Styling sandcastle that occurred when using ModelExperimental. https://github.com/CesiumGS/cesium/pull/10514
• Fixed a bug where dynamic geometry was not marked as ready. https://github.com/CesiumGS/cesium/issues/10517

See the changelog for the complete list of changes.