Understood. You have asserted that many times now. But what you are trying to say has not been made clear.

Let's break this down. As defined by context, OOP means: messaging, local retention and protection and hiding of state-process, and extreme late-binding of all things. Indeed, there exist other OOP definitions, but that is the one that was defined here.

I think we can rule out "local retention and protection and hiding of state-process" from the discussion. Hiding means that even if there is some kind of relational database access happening behind the curtain, we cannot know about it. If we don't know about it, we cannot talk about it.

That leaves messaging and extreme late-binding. It is not clear to me what it is about messaging and/or extreme late-binding that is at odds with relational databases. This is where I seek clarification.

While you pointed to the work of Neward and Atwood, all I could find from them was discussion about the pitfalls of trying to model relational databases as a particular object model. They say nothing about messaging or extreme late-binding. Unfortunately, they were of no help here.