We recently reported that the new Metro game in the series was expected to launch next year ,based on a timeline on the official website for the Metro 2035 novel. That has been confirmed to be not true.
Deep Silver, the publisher behind the Metro games, has flat out denied that claim. They have stated that “Deep Silver has ambitious plans for the hugely successful Metro series. But just to manage our fans’ expectations – releasing the next Metro game in 2017 is not one of them.”
That brings into question what the timeline is actually referring to and unfortunately at this time, it appears that no one knows.