When selecting an XML with not registered CLSID's there should be shown a warning: XML workspace contains 6 unregistered class types, are you missing an extension?
When you export these aprx with unknown to an enterprise geodatabase this will result in the following error:
An esri table feature has a fixed Class ID (E.G.) <CLSID>{7A566981-C114-11D2-8A28-006097AFF44E}</CLSID>
A random CLSID is mapped to am extension class. If this is not installed as a service object extension this will generate an error when queryng this record.
The above changes will make it clear what action would be needed.
