Aegis Boon, Holy Succor and Divine Veil/Regen would be great abilities to have back. People saying them having heals wouldn't make sense because of their lore as Sultanate knights also forget they have an ability called Rage of Halone, named after a deity mainly worshiped by Ishgard and not really related to Uldah. If anything them having heals would make sense because Uldah's main deity is Nald'Thal and that deity's aspects are life and death, curing is all about giving life so there you go.