Proposal: Grouped symbology from ArcMap should carry over to feature services.
This idea has been merged with Group layers for ArcGIS online.
Problem: Similar categories of features in ArcMap that are symbolized the same way using the Group Values function are ungrouped when the feature service is created. This creates legends with several of the same values listed multiple times. ArcGIS Online does not have a function to re-group these values.
Idea: Allow Group Value symbology to carry over to the feature service.