For ARR we got Shiva, Ifrit, Garuda and Leviathan gear sets for certain jobs in the form of Hailstorm, Hellfire, Slipstream and Torrent gear.
I’d love if we got some of these for HW and SB Primals.

Most notably I think it would be awesome to get:
Sephirot Slaying/Scouting gear
Sophia Healing/Casting/Aiming gear
Zurvan Maiming/Fending gear
Byakko Slaying/Scouting gear
Suzaku Healing/Casting/Aiming gear
Seiryu Maiming/Fending gear

This would provide us with similar styled stuff but for different roles. E.g. The Hellfire stuff is currently melee jobs only, but this would provide a fire themed set for ranged from Suzaku.
And the Torrent stuff is currently physical ranged and Ninja, but Seiryu would provide water/serpent themed gear for Dragoons and tanks.

I would grind the hell out that Suzaku caster gear for my complete Rez Mage glam!