Game progression. Chocobo is unlocked via seal grinding once you've joined a Grand Company. Unicorn is a CNJ30 reward, and Magitek is a main story complete reward. TBH I wanna see a Drake Mount(DRG) & Behemoth Mount(WAR).

Coeurl and Ahriman are CE & Veteran awards, and players from v1 can have a Goobue and Legacy Chocobo, but only if they met the conditions from v1.