Fusilier/Mog Knight with Ultima Charge & Concentration was teh *** in FFTA2. Nothing quite like an 8 panel range Ultima. That Moogle ended up being one of my highest leveled characters after Luso and Cid.
I went the "Hey let's give this Parivir Geomancy and watch as he lolfacerolls everyone," or the "look at me i'm a paladin i'm overpowered" route. The game wasn't really good enough to put vast amounts of time into like the first one was, so I didn't go as far as to optimize things. Besides, humans and bangaa had ranged ultima too, via Hunter, which had nerfed stat growth from the first game, but more functional abilities. Or Trickster, which had a wider range than any other ranged in the game.
They could combine Gunner and Cannoneer with the functions of Corsair, minus the dice and cards. Give them special ammo to boost the HP/MP/TP of party members, or enfeeble foes with elemental shots.
They could, but their whole plan was to run with less jobs that could do more. Bard is more open ended as far as what they can do, since they could also combine Bard with Dancer and have a support class that has a sort of offensive healing. (Think Judgement of Light in World of Warcraft.)
Granted, this is all speculation, but I just don't see Cannoneer making an appearance. It isn't as prominent a class as most, and you know how they love to stick to the popular classes.