You are correct. Unless LaTech gets a 7-5 or better at-large to come to Shreveport, looks like the Cajuns are going to the Indy if they beat MT.
Another scenario would be Boise vs. Ball State, but that seems unlikely.
Looks like it's going to be LaTech vs. Cajuns or LaTech vs. stAte, based on the iron-clad Indy Bowl contract that Wright Waters has in his office.