I had an idea I wanted to drop on everyone to preserve the primal fights throughout the storyline until version 2.0 came out.
Step #1: Make all the primal loot equivalent to each other except for the added elemental effect. So for example: Ifrit Axe has XX about of dmg and so does the moogle axe but Ifrit has added Fire and Moggle has maybe added Wind. In addition to the elemental effect they can add individual stats based on the element of that weapon. EG:
Ifrit's Axe: Atk Power +, STR+ (raw power)
Garuda's Axe: Critical Hit Rate +, DEX+ (hit more often)
Titan's Axe: Parry Rate+, VIT+ (tanking axe)
So outside of primal fights you can use whichever weapon you want based on the extra stat depending on the situation or content you're trying to nail which will give us a sense of choice and individuality to our characters. (Assuming they keep releasing dungeons alongside primals)
Step #2: As the primal battles are released let's make the new primals element weak against the old primals element. (I don't know what the element chart is) So the moogles can weak against fire so there will still be incentive to get Ifrit weapons to defeat the Moogles easier. Then the moogle's wind weapons will be used say against Titan because Titan is weak against wind, etc.
Step #3: After however many primal battles they squeeze in, you need one from each primal battle to forge the "Ultimate Weapon" and then they implement Bahamut (who if I remember right is non elemental) as the last primal battle before 2.0, who, although you win the fight, maybe does some crazy shit to end the world and revamp Eorzea into 2.0!
In short, all primal loot should equal save for the elemental effect and a stat based on that element, and the next primal should always be weak against the element of the current primals loot. Then we use all the weapons to make the "Ultimate Weapon" and slay Bahamut who destroys the world and /hello 2.0!
Like this post if you like the idea! I really hope you guys do!
(Edited to add Kailoks idea)