When I read this, I was very surprised that the word "characters" was used. One, this is supposed to be a reality show (i.e. entertaining quasi-documentary), thus the participants are not fictional.
If they meant characters, as in crack-ups, or Herb-types, well then that may fit, but that was not my read on the press release.
Southwest is normally very precise about how it treats its People, so I am surprised that Southwest allowed this terminology to be used. I guess its not their show. Maybe this is nit-picking, but Southwest normally takes great pains in keeping its focus on its People, not its "characters".