In Fivetran's connector for Facebook Ads, records are updated every time even if they are "deleted" in Facebook: https://www.facebook.com/business/help/991073724257797
The object entity still exists in Facebook, but it has "status=deleted". Note that "deleted" just is a Facebook-assigned attribute. It does not generally mean that the record does not exist anymore. Thus APIs will still return data.
The consequence is that Fivetran connectors will use up MAR to update useless data -- effectively consuming credits for data that I do not care about.
(This request is related to private issue #57367 I was working on with Rory Hewson.)