Visit the Oracle Eloqua 20A (Feb 2020): Customer Release Info page for an on-demand briefing and a complete list of all of the features included in the 20A Release.
Here is an extract of all the Developer Updates:
accountId will now be returned at complete depth when retrieving, creating, or updating Contacts using the Application API when the Contact is linked to an Account.
As part of the Classic Design Editor changes, the Create a form Application API Form endpoints will not allow you to create classic design editor forms and Update a form Application API endpoints will not allow changing a form from responsive to classic.
You can now set the status for all records in an execution using just the execution ID. The new updateAll parameter determines what status to set records in an execution, when creating a contact or custom object sync action definition.
Resolved an issue where it was possible to create export definitions with a dataRetentionDuration of null, resulting in data being deleted sooner than intended. Now, dataRetentionDuration can no longer be set to null, and the default duration will continue to be 12 hours (ie. PT12H).