Which comes from a recent interview between studio head Chris Roberts and German magazine GameStar. So even though the official website still lists Q4 2016 as the release date for the star-studded Squadron 42 campaign, apparently that's now the more likely windows of the middle to the end of 2017. Naturally the delay is due to the game not being ready, with stuff like AI and the cover-system cited as still needing work.
Of course the source could be wrong and Squadron 42 releases as planned in the next couple of months. But then again, a delay isn't all that surprising considering we haven't really seen in-game footage of Squadron 42 that you would consider to be "final". Or that the bulk of the Gamescom focus was on the new planetary landing stuff for the still-to-be released 3.0 Alpha.