This morning we reported that a new Metro game based on the book Metro 2035 had leaked and would be released next year. Now the publisher of the games, Deep Silver, has commented on this official saying they've got "ambitious plans for the hugely successful Metro series", but adding that "releasing the next Metro game in 2017 is not one of them".
So there you have it. A new game will obviously come at some point, more or less confirmed since they say that they have plans for the series, but we shouldn't expect it during next year. At the other hand, releasing a game is not the same thing as an announcement, so hopefully we can still get the latter.