Multiple sites quoting the same soundbite doesn't make it correct.
Plus even the supposed french origin (Béton brut) is derived from the word brutal...again predating concrete. Beton = Concrete, so even that "origin" is fairly recent.
I don't necessarily disagree with your main point — I don't know enough to say either way — but that statement isn't true unless I'm misunderstanding something.
Concrete was used extensively by the Romans, and also before them.
The earliest citations in the OED for "brutal" are 16th century (in English). (It also says "Compare French brutal, 16th cent.") It is derived from a Latin word, but even then it likely doesn't predate concrete.
Really? I would have thought it's derived from the term brutal, which predates concrete.