That article does not convince me, scope guard + lambda appears to work just as well as finally, and is actually shorter(see tianyuzhu's comment)
I do not know if anyone has proposed it for C++, but I would be surprised if it passed given that it doesn't accomplish much.
(also I totally disagree that RAII is superior to finally. Finally, being lexically scoped, is far simpler, far shorter and far easier to understand. https://codecraft.co/2013/10/31/why-we-need-try-finally-not-... )