New GC gear?

[Arasiel]

There is a new chest and head but says not high enough rank to buy... Go apply for promotion and says I'm max rank

[Maero]

There was another thread about players unable to get promotions,
perhaps this is the same issue.

[Lukha]

Previous ranks required you to complete the GC hunt log in order to unlock them, as well as pay a fee in GC seals. Is it possible you're at the 'max rank' because you haven't fulfilled the requirements yet?

[Alberel]

It's heavily implied during the introduction to GC Squadrons that you need to reach some milestone with your squadron to unlock the next GC rank. It's not bugged, people just haven't figured out how to do it yet.

[Niwashi]

Previous ranks required you to complete the GC hunt log in order to unlock them, as well as pay a fee in GC seals. Is it possible you're at the 'max rank' because you haven't fulfilled the requirements yet?

Max rank has never before meant the rank you're entitled to. For all previous ranks, you could ask about the next promotion and be told what its requirements are. It's so weird for that info to be lacking here (and even stranger that even the existence of another rank is denied in the dialog like that), that I'm thinking it's probably a bug in the new patch, where they forgot to update the NPC's dialog. (Not a bug in whether you can rank up or not; that's most likely working. But it seems like a bug for the NPC not to tell you about the next rank.)

Patches are often followed by a hotfix taking care of several minor issues. Maybe this one can be fixed then.