The last convincing clue about the existence of a new Shadow of Mordor game was when the game was spotted in the CV of a stunt actress. At that time, everybody thought that we will be hearing about the game last year but that never happen.
Since then, the hype for the sequel has died down significantly but that does not mean that the fans have given up. Warner Bros has recently announced that they will be making an announcement on the 8th of March 2017.
While they did not reveal the game that they will be announcing, some fans think that it might be the Shadow of Mordor 2 that we have been waiting for. There are other who think that it might be a new Batman game based on the art style of the logo.
As of now, all we can do is guess but luckily a month is not that long of a time.