It came to light a couple of days ago that Ubisoft's Watch Dogs 2 contains a "leaked" trailer for an entirely separate, vaguely No Man's Sky-looking sci-fi game of some sort. It was, on the face of it, a very meta joke, riffing on Watch Dogs' real-world setting and the real problem (in the view of publishers, anyway) of game leaks. But some people suspected that it's actually a real trailer, for a real game—and according to Kotaku, they're right.
The site said today that two sources have told it the game in the trailer is a space exploration game code-named Pioneer that was supposed to be announced in 2017. It's apparently run into trouble, however, and its status is now uncertain: The game is in the process of being "retooled," one source said, and the planned announcement has been put on hold. But development schedules being what they are, the trailer was inserted into Watch Dogs 2 before Pioneer went off the rails, and so here we are.
The whole thing is entirely unsubstantiated (although Kotaku has a good record when it comes to these things), and so there's no indication as to what specifically is responsible for Pioneer's problems. One obvious possibility is that the No Man's Sky resemblance runs deeper than mere visuals. Ubisoft may have been hoping to tap into its success with a similar game of its own, but given how badly NMS crashed and burned, even a superficial similarity is almost certainly seen as pure kryptonite these days.
I've reached out to Ubisoft for comment on the report, and will update if I receive a reply.