Problem Definition
The Insight audit logs only show object related events such as creating objects, deleting objects and updating attributes.
When an attribute is added or remove from an object type, we don't log that info.
This is important because deleting an attribute from an object type will effectively delete all attribute values from all objects of that object type.
Same applies for any changes in the Import Configuration (Object Type mapping).
Suggested Solution
Add an option to log object type events in the audit logs.
Workaround
Inspect the access logs for PUT/POST/DELETE to /rest/insight/1.0/objecttypeattribute/.