The original poster's parameters weren't quite observed, his question is "is there a workflow to... synchronize the validated/updated data set back to the “original” file geodatabase". Oftentimes we don't get to choose where data resides.
Question restated: by what process, set of steps, and products does ArcGIS accomplish the transfer or joining of the newly collected (or updated) data with its corresponding dataset/Enterprise Geodatabase Feature Class, whether it resides on a single PC or server... and if I might add, in sequence with the next objectID of any given feature.
Neither uploading tens or hundreds of thousands of assets to ArcGIS Online, nor subesequently overwriting tens or hundreds of thousands of assets in a feature class in order to add five new ones, is a sustainable or acceptable data management practice either. Just hoping for some added insight.