AspyrWoo posted this on Steam earlier today:
"Hey everyone, status update on the Summer 2017 Patch for Mac/Linux:
It is with huge regret and sad faces that we, again, have to delay the release of cross-platform multiplayer.
We are moving forward with the launch of the Summer 2017 Update for Mac and Linux, which will offer all of the available content as the Windows update. After thorough investigation, we’ve decided that we cannot hold back the content any longer in lieu of some nasty cross-platform bugs.
We’ve consistently stood behind a quality bar for our products, and it’s a standard that our partners and players have also come to expect. For those of you who were looking forward to cross-platform multiplayer, we urge you to understand that should the feature have come into the live environment, desyncs would have been guaranteed and frequent to the point of an extremely poor experience."
Incredible! Cannot believe it myself, but DLC05, Summer 2017 update, will be released shortly, I am assuming. The files on the Steam Depots have been updated twice so for today. Enjoy the update!