Will Black Mages ever get Ultima?

[Enkidoh]

Considering Gaius was entrusted with it, and failed (although to be fair he didn't even know the spell was contained in the Weapon's core)... I don't have much confidence in BLM ever getting it I'm afraid.

(That and the spell was lost when the Ultima Weapon exploded).

No it’s going to be the blue mage limit break. They’re changing up the ultimate weapon fight so you can survive the “enrage” one with the blue mage damage protection shell, and that’s how we will learn it.

Ironically enough, this was more or less how it was learned in FF Tactics - a certain enemy in a particular battle would use it and Ramza had to be his starting Job class (Squire) and be hit by it (and survive!) in order to learn it, it was the only way to get it in the game (this explained why Ramza's Squire Job never stopped gaining JP even after unlocking all abilities and traits). So, there is precedent (Ultima after all in many FF games is not considered Black Magic or necessarily associated with the Job exclusively).