I can assure you Rockstar is swimming in money from their GTA V sales.
A big company needs money flow, so why not release it this year, if nothing else?
Right, as if they don't have the money right now
Because they made one big sale, that calls for slowing down production. No.
Plus, they are probably using all of that money on making their next game/s, therefore the faster one comes out, the faster they make money. Another year, probably equals $100m spent and with the new gen out, why not release something to get money?