2016-11-14 Update – It seems this has been removed from the Current Channel and it’s back to the old UI, I’m trying to get an update on the plan. Will post as soon as I have an update. Thanks
2016-11-17 Update: Build 1610 does not have the UI changes included. Unfortunately, Microsoft encountered a last-minute problem with the UI check-in fork and as such, it didn’t get applied to Build 1610. Due to internal timings and deadlines, it didn’t make it to build 1610 CC release. I am told the PG were able to make the change in the next build and the UI will be in the next update to Current Channel, which might either be early next week or the week following Thanksgiving.
2016-11-21 Update: It’s now back in Current Channel again
Microsoft mentioned this was coming in an October Nexthop Blog post, and it just came to my machine on click to run 16.0.7369.2055, which reports as First Release for Deferred Channel
Why the changes?
From Microsoft: The new client visuals are part of a large amount of work (both visual and internal) Microsoft has done to make Skype for Business 2016 more accessible so that it can be enjoyed by more people around the world. One example of this effort is the slight variation in color changes which provides greater text-to-background contrast to empower those with low vision to more easily distinguish parts of the interface. We also improved screen reader support, simplified keyboard navigation and made the keyboard focus easier to see in many places. For more information on the overall goal of Microsoft to enable all users go to: https://www.microsoft.com/enable/
When will this happen?
Early Adopters on the Current Channel and First Release for Deferred channel will see these changes now (November 2016), whereas organization members on the Deferred Channel will see these changes in February 2017.