Tennessee voted to remain in the Union, but that didn't stop the slavery lovers in the legislature from ignoring the expressed will of the people in taking Tennessee out of the Union and inviting the rebel hordes in to "defend" the state.
None of the original 7 and eventual 11 ordinances mentioned slavery as a cause of their decision to leave the Union.
The 11 ordinances didn't give ANY reason for separation. They were only legal documents stating the facts. The justifications were the parallel documents giving cause.