> He literally gives extensive primary source citations to show that the originators of OOP presented this class-domain correspondence

In case of Dahl/Nygaard it seems logical since their work focus was on simulation. Simula I was mostly a language suited to build discrete-event simulations. Simula 67, which introduced the main features we subsume under "Object-Orientation" today, was conceived as a general-purpose language, but still Dahl and Nygaard mostly used it for building simulations. It would be wrong to conclude that they recommended a class-domain correspondence for the general case.

> Bjarne Stroustrup is not just some random guy

Sure, but he was a Simula user himself for distributed systems simulation during his PhD research at Cambridge University. And he learned Simula during his undergraduate education at Aarhus, where he also took lectures with Nygaard (a simulation guy as well). So also here, not surprising that he used examples with class-domain correspondence. But there was also a slide in the talk where Stroustrup explicitly stated that there are other valid uses of OO than using it for modeling domains.