Sigma 70-200 f/2.8 OS Sport & Sigma 70-200 f/4 OS Contemporary Coming? [CR1]

We're told that Sigma will be announcing two new 70-200mm lens in the early part of 2018. One of the lenses will be a 70-200mm f/2.8 DG OS Art series lens, and the other a 70-200mm f/4 DG OS contemporary lens.

The 70-200mm f/2.8 DG OS Sport has been rumored for quite some time, but this is the first time we've heard about an f/4 contemporary version.

This sort of announcement would make some sense for CP+ in February, I'm not sure CES in January is the place to announce these lenses.

This comes from an unknown source, so treat it accordingly.