This certainly sounds like someone had been threatening something other than Abolishion and emancipation. I agree that the word disunion could mean disharmony, unrest or even war between peoples but that doesn't sound like what is being talked about here. It sounds like to me here someone had been talking about Disunion, meeting secession.
If disunion were in fact a code word for "war" used by the abolishionist in order to emancipate the slaves, do you mean to tell me that the Northern states were in favor of that? If so that would have been even more reason for the Southern states to seceed and govern themselves.