Hi Kimberly,
Thanks for the feedback. Parquet feature layers are currently in beta and do not yet support storing or applying predefined symbology as part of the layer itself. A common workaround is to configure the desired symbology in a web map and share the map with users.
Support for layer-level visualization properties is something we're actively working on for Parquet feature layers. We recognize the importance of authoritative datasets, such as statewide vegetation layers, carrying their intended symbology so they are ready to use with a consistent cartographic experience. We appreciate you sharing this use case.
For a comprehensive list of current limitations please review the following blog: Scaling your GIS workflows with the new Parquet feature layer (Beta) in ArcGIS Online
