I can understand if it takes up months or even weeks of development time but this change really is incredibly trivial to implement - as anyone who know anything about programming can tell you.
The art for the Carbuncles is already done. The code for summoning and controlling the Carbuncles is also done. Adjusting potency values can be done in a few keystrokes as can copying-pasting 2 skills to SMN's spellbook.
Just skip that. No one uses Ifrit anyway. xD
With regards to their plans for 3.0, it's really more of a personal observation than stating of facts.
Having played WoW for over 8 years, I know how their classes are designed and why. FFXIV just seems to be going down the same route - Yoshi-P is after all a fan of WoW, so he replicating their class design isn't surprising.