Why Am I Seeing Delete API Calls in My Salesforce Connection Logs?
The DELETE method API calls you see in your Salesforce connection logs are related to Fivetran's use of the BULK API. These calls remove completed query jobs that we create while syncing data. They don't indicate that we're deleting Salesforce data.
For more information about the DELETE method API call, see Salesforce's Delete a Query Job API documentation.