Obviously not, and bringing this up as if it's a gotcha just shows you aren't keeping up with the conversation. Try less to correct people and more to understand people.

It's about how humans think about it, not about how the computer executes it.

How else do you read what they wrote?

I read it as describing their preferred mental model for declaring a result set, which is different from describing their preferred behavior to produce it. This seems clear to me in wording and context; it’s also broadly consistent with how SQL is understood, and how it is generally implemented.

Presumably, the intermediate result sets would necessary be materialized, only logical.