It's obvious that Square wouldn't want weapons overlapping between jobs (new job with a hammer/bow probably won't happen)

The only two I could see them adding that are vaguely similar to older jobs are a dual wielding job that uses regular swords, instead of the NIN "daggers" and maybe a dual-gun job that's not steampunk like MCH is.

Other than that the new jobs could have a Whip, Mace or a Crossbow... again, not a lot of options left unless they come up with something new like with SGE/AST