I find this article amusing because the clue is right there in the name.

Received Pronunciation is just that, received.

You can learn it, in fact it has been and continues to be taught both in schools, in elocution lessons, and in educational videos online.

I sincerely doubt that this is a purely UK based phenomenon. The example that comes to mind is the stereotypical "black man with white accent" from US sitcoms. I don't know how that works in the real world, but I'd feel fairly confident in placing a bet that there aren't many white collar CEOs who sound like they're from the hood.