When Big 12 presidents and athletic directors begin meeting Thursday at the Dallas-Fort Worth International Airport Grand Hyatt, might as well bring your popcorn. On the agenda is Gonzaga’s potential membership in basketball. That alone has realignment implications beyond the Big 12. There will also be some discussion about the possible early exit of Texas and Oklahoma for the SEC. Going into its first season with new members BYU, Cincinnati, Houston and UCF, the Big 12 will discuss perhaps its only athletic year with 14 teams. That’s a Texas-Oklahoma issue, too. Expansion is still in play, especially as long as the Pac-12 doesn’t sign a new media rights deal. Gonzaga’s…