Sounds like another reason for the rejection is not having that 14th team yet, and some complications arising with the potential teams named (Clemson, Mizzou, and FL ST.). An article in the Atlanta Journal Constitution suggests this and says they are looking elsewhere for the 14th member school:
Atlanta Journal Constitution report on SEC Meeting Today.
The only potential barrier to an overwhelmingly favorable vote by SEC Presidents....the sticky problem of who to invite as a 14th Member. One insider suggests Louisville would present the fewest obstacles, provided UK does not object.