I think it's natural for any employer to offer benefits and also respect negotiated work rules; it appears that for AC they include front-cabin seating before customers requesting certificate upgrades, which are in fact offered in advance but capacity controlled. You do have the option of securing a seat in the J cabin by purchasing a fare valid for that cabin; there is no entitlement otherwise if you decide to take your chances with certificates. I look forward to "playing the game", and will welcome any upgrade that falls my way by the luck of the lottery.