Also, there is this from the Creative Commons website: "The latest version of the Creative Commons licenses is version 4.0. You should always use the latest version of the Creative Commons licenses in order to take advantage of the many improvements described on the license versions page. In particular, 4.0 is meant to be better suited to international use, and use in many different contexts, including sharing data." (https://creativecommons.org/faq/#why-should-i-use-the-latest-version-of-the-creative-commons-licenses).

That was my bad. I had gotten in touch with legal and felt encouraged from the discussion with them to suggest moving the footer forward to 4.0, since that seems to be where things are headed. Perhaps the move to do so was still premature. (How/ When will we know when that is no longer the case?).