When the Geodatabase writer creates a new table, it looks for the geodb_type specified on the feature type.
For a list of the valid geodb_types, see Feature Representation. If the geodb_type is not valid or is not found on the feature type, then the geodb_type attribute will be retrieved from the first feature headed for that table.
In the unlikely occurrence that the feature does not have a valid geodb_type or any geodb_type, then a warning will be logged, the writer will assume that the geodb_type is geodb_type, and a non-spatial table will be created. As a result, all features of that feature type will have their geometry ignored.