Does any one know if Leviathan Egi will replace ether Garuda, Ifrit or Titan?

Like the way Titan and Garuda became new skins for Emerald Carbuncle and Topaz Carbuncle.
Which in my mind seems stupid cause the only way you can Summon any of the 2 forms of Carbuncle at level 50 is go back to Arcanist (sorry about spelling) as your Class Job.

I don't understand why we can't summon normal Carbuncle at level 50. With out the fancy names added to him. I hope Fenrir doesn't end up sucking hard core in the futre cause Fenrir was always my favorite summon.