I actually do remember Dia and the like, Lemuria. I've been playing XIV since 1.0 alpha and played FFXI from PC release until WotG.

The class system feels weird and unfinished. My thought is just that they should continue to flesh out the jobs we have before they move on. Astro and Machinist look like interesting classes, but they shouldn't have been created before they accounted for half of the magic that's missing from this game. I know XIV isn't XI or any other previous FF, but there are certain things that shouldn't be overlooked and excluded.

They can't create a whole new class to have these elements without completely revamping the entire current class system (which they very well may do at some point?), so creating it as an offshoot of CNJ would fit the lore pretty well imo.