Preorder comes with a Zidane minion (protagonist of FF9) and an EXP earring.
Digital collector's edition comes with a Garnet minion (deuteragonist of FF9), an Ark mount (boss/summon from FF9) and a Chocobo Brush weapon for Pictomancer.
With how heavily they're leaning into FF9 with the bonuses, I am very surprised the collector's edition weapon isn't the Ogre/Mage Mashers from FF9 for Viper.