He wasn’t saying these were facts.
These are the assumptions generally held by the progessive / left.
By comparison, look at the assumptions held by the right in the other post.
These aren’t what’s true, they’re what’s implicitly assumed in overall thinking.
For analogy, generally people who use logic know what it has a historical foundation and do not believe it is the underpinnings of the Universe
But they act “as if” it’s the underpinnings of the Universe when doing dialectic or other truth-seeking methods using logic.
Someone who believed logic is the foundation of the universe was an idiot who doesn’t know history, just like someone who believed the things he said above in reality would be an idiot.
But they still are underlying assumptions – a backdrop of general belief.