Mythic Weapon...but not a Captain

The FFXIAH.com page shows that Kirschy has acquired a Liberator. This is verified by the LS Community Beta site and, I'm pretty sure, friends have seen him/her in-game with it. Congratulations, Kirschy!

However, the FFXIAH.com also says Kirschy is only First Lieutenant rank and you need to be Captain to even start An Imperial Heist, the 1st Mythic Weapon quest.

I guess the wiki could be wrong but don't you have to complete all Assaults as part of the quests? Would you not get your rank up when you did those? I'm guessing the rank shown on FFXIAH.com is wrong...somehow.