Looks like Canon USA messed up and re-used the description from the 5DIII's BG-E11. The 6D doesn't have a multicontroller on the body, I would not expect one on the grip...and the pics confirm that.
I emailed Canon and they confirmed that the grip DOES CURRENTLY HAVE both a multi controller, as well as a M.FN button.
The CSR that responded to me didn't give any explanation for why the photos don't show it, other than to say that it had been released in a very limited quantity and that there might not be "very many reviews" on the exact grip.
While I find this a little hard to believe, until I have one in my hands I can't say for sure whether it does or doesn't.