I'm on the team of the "Scythe-wielding" job that is dark themed, by the following reasons:

1) The shirts, obviously - It doesn't mean that just because it's a melee that is not themed around magic skills, much like DRK;

2) The WoL poster-boy is a paladin. It would make sense for a counterpoint job, dark themed, but defo won't be DRK for the obvious reasons of it being featured in ShB. This point is mostly vague, but at least might be a hint about the theme of this new job. I can't help but look at Amano's art for the xpac and think about a job that is somehow themed after Zodiark/Ascian power/Void wielding?

In short, I don't think it's going to be Necromancer... But a job that manipulates Void powers and wields a scythe.