Yes, JMU is a pretty smug fanbase, and they'll be that way win or lose. The key is, don't lose, they are much better to deal with if you hang an L on them.
I don't think it's an east coast thing necessarily. Upity universities folks are smug, JMU meets that criteria. Big city folks out east on the other hand like NY, Boston, DC . . . are intentional about putting down anyone in a flyover state, it's just their nature. They are not as dumb as they try to come off, it is intentional to put others down. Don't know where Montana is? Come on I don't buy that, it's just their way to be superior.