The delegation of authority was a Bush Jr. policy about deregulation and making airline aviation "more agile" or some other BS. It involved defunding FAA effort

The delegation of authority was a Bush Jr. policy about deregulation and making airline aviation "more agile" or some other BS. It involved defunding FAA efforts at control and explicit policies for more self-governance in the industry. There wasn't a "bad deal grandfathered" - there was a general acceptance of FAA flight certificates in many regulatory areas due to previous good performance of those, which was wrecked by 737 MAX crashes. Even then it wasn't automatic pass, it was more that local certification authorities would let you submit it in lieu of some checks but could require more. Also, apparently Airbus has wildly different policies for dealing with suppliers, which are seen as both bad (they aren't easy to work with and most importantly they mean more risk to supplier) but also good (better oversight, integration, and Airbus will actually help you deal with your suppliers, and the risk is shared)