Unfortunately no it is still base game, but you are doing the right thing still as Square Enix simply updated the package to Definitive Edition, so it is impossible to select the base game any more.

Worst thing about Square really, they are updating the package from base games to Definitive yet don't upgrade people who already own the base game. It would be much simpler to just keep offering the base game and create a new package for the Definitive ... BUT NOOOOO! :P

Regardless the winner of this giveaway still has the ability to upgrade to the Definitive Edition, they just need to know it is only base game that will activate ... fingers crossed I get lucky and you don't have to say anything :P