What exactly does Congested mean and will it ever go away?

[Gamefreak]

Congested is a tag that Square manually applies to a world making it so character creation and transfer isn't possible until Square themselves manually remove the status. I don't get why Aether is still locked when many of the worlds on that data center are averaging the same login queue numbers as some of the servers on Crystal and Primal. I can't play with any of my friends because they are all on Aether...

No clue when they are going to lift it but they seem to be extremely lax with their congestion removal usually making people wait until the next patch before they remove it (and even then there is still the "Creation of New Characters Unavailable" tag). It's entirely possible that you might never get to play on Aether with them unless Square finally fixes their server structure that has been questionable for years now.