This is controlled from the DxDesigner.xml file under <PackagerUI> section but cannot be restricted at the moment as some other settings can be. In general the only issues that you will get are with properties that exist in both places and these are usually Value and Description in parts translated from DC. In the case of description you can remove it from the PDB or make it match what is in DxDataBook (if you are using it from there). Otherwise change which properties get annotated from DxDataBook to the schematic so you don't get conflicts.
Thanks for the input. Perhaps as things "evolve", they will add the ability to disable this for folks like us who are wanting to tightly control the integration with DxDatabook. I suppose I can always go add this feature request at the "ideas" site.