Did the game get gold etc? How many worldwide sales, USA, UK etc?
How much money have they made?
Will it be enough to ensure version 4 within 1 year?
I would say sales will continue at a steady pace since I see mostly positive reviews and mainly by players who will be the biggest seller as word and mouth will continue to sell the game for months to come...
You want a new version released within a year? Sure, Call of Duty does it, but it's two separate companies using an identical engine to the previous game. I would expect Far Cry 4 to be released in another 4 years or so. Just like other games of its type. Plus it would match its release pattern.
Far Cry - 2004
Far Cry 2 - 2008
Far Cry 3 - 2012
Of course, there's always a chance of a spin off.