So yeah, old gen versions are coming but Treyarch is not working on them, and they're being hidden, ala Titanfall 360.
http://www.eurogamer.net/articles/2015-04-26-call-of-duty-black-ops-3-pc-requirements-revealed
http://www.eurogamer.net/articles/2015-04-26-call-of-duty-black-ops-3-pc-requirements-revealed
"We're working on Xbox One, PS4 and PC. That's it," he added. As for other platforms such as PlayStation 3, Xbox 360 and - stop smirking at the back - Wii U? We were directed to Activision, which said it had no further platform announcements at this time.