As with Web Maps (both classic and beta), Web Scenes should allow the rotation of point symbols based on an attribute field. In a Web Map, I've ensured the rotation field is an integer type and verified the rotation option is viable in a test. Currently this feature isn't present in Web Scenes, the same feature layer was used.
The only work around I've been able to implement is to symbolize the feature by unique value (set to rotation field) and have a separate symbol for every value. This is not conducive to a clean legend and requires excessive work to account for.
Please add this option to Web Scenes.