Nope, and it's not coming in the base game either. Any reports of apparent dual-wielding on the "Mysterious Stranger" were erroneous or graphical glitches.
That's certainly a peculiar and outstanding bug... that is able to add dual wielding animations.
I think game studios should hire this bug to reduce high animation costs.
Or maybe we're all hallucinating and the character in the youtube video is not attacking with both arms.
