For starters, with each expansion, they've had a different "Motif" or "Theme" for how they want all Jobs to operate in general, so first off, I expect them to have a new one. For HW, it was buff maintenance (Greased Lightning, BoTD, Enochian, Huton, Dreadwyrm). For SB, it was giving each Job their own meter/resource.

For SHB, my theory has been that they'll give everyone something that expands their resources further. For DRG, being able to get a fourth eye during LoTD, to go PAST LoTD. For BLM, gaining more Polyglot stacks to cast something PAST Foul. For MNK, GL4. Etc etc.

I expect something like an "Ultimate" ability that takes our resources from 100 to 0 for an incredible burst of damage, or an incredible buff.

More traits.

For Dancer to be their solution to the DRG monopoly on "Synergy with ranged physical DPS", through nature of Dancer being Slashing damage and relying on SAM/NIN.

Dancer will be the NIN of physical ranged DPS, MCH will turn into the selfish (SAM) physical ranged.

Dancer will be more mandatory than any Job in the game ever has been.