It is practically unheard of for a MMA fighter to make his debut on pay per view. As a 0-0 fighter, Punk is ridiculously unproven. However, all his value is wrapped up in the first fight. People will pay money out of curiosity to see that first fight, so it would be dumb to throw it away on a tv special (although it would pop great tv ratings). Usually, a fighter needs at least three pro fights to compete in the UFC. Punk is going in with 0. Despite this, he told Ariel Helwani that he believes his first fight will be on PPV, so this one looks a definite. As for his position on the card, he won't be the main event, but he will be the top of the undercard. You can expect to see him on the event poster because he'll be what's selling the show, but the top of the card really needs to always be proven fighters. It would be a massive risk to put Punk, a 0-0 rookie, as the top fight of a UFC PPV.
