Per my source in the NCAA offices in Indianapolis . . .
Dennis Poppe, the NCAA's Managing Director for Football & Baseball, reviewed the contracts between the Sun Belt Conference and the three bowls; Independence Bowl, PapaJohns.com Bowl and St. Petersburg Bowl. After reviewing the contracts he has ruled in the SBC's favor and decided the agreements are valid and binding regardless of whether Sun Belt teams are 6-6 or 7-5.
If there are no 7-5 teams in the country available to fill the Indy Bowl slot then the Independence Bowl is REQUIRED to offer the open spot to a 6-6 Sun Belt Conference team. Same goes for the PapaJohns.com and St. Petersburg bowls. The only way a 6-6 SBC team can be denied playing in one of these bowls is if if the original conferences contracted by the bowls provide eligible (6-6 or better) teams to fulfill the contracts, or one of those slots are filled by a 7-5 or higher team from all at-large teams in the country.