Like others have mentioned you will need to clear Turn 1 to 5 before you can do Turn 6 to 9.

They will also remove the weekly limit on T1 to 5, so most people will probably start farming 1 to 4, so most people will easily be ilevel 90. I also heard speculations that Leviathan EX will be dropping ilevel 95 weapons, but I honestly think Leviathan will be dropping ilevel 90 chokers, be great if someone can verify.

They will also implement a nerf to T1 to 5 (or buff to be exact). Every week after 2.2 goes live, players will get a buff (I believe they said it was called "Echo") which increases your group's power. You gain more stacks every week I believe, still too early to tell.