This has probably gone through everybody else's minds already, but what if they are just not fixing the "bug" on purpose. As they said, the mission will be expanding further, which in my way of thinking means the Arcade being longer. Now, with the first arcade redux update, they might have just added this feature already, while the levels don't exist yet. They don't seem to be fixing it, even though there is much demand for it. So what if they really are just adding new depths to the Arcade, just not now?
Edit: Please do not start a new thread about a topic when there is already an active discussion thread. Thanks!
New depths would mean new rank items (6*) will be introduced.
5* items will still be for stratum 6. It goes like this:
Stratum 1 - designed for characters with rank 0 item (0*)
Stratum 2 - designed for characters with rank 1 item (1*)
Stratum 3 - designed for characters with rank 2 item (2*)
Stratum 4 - designed for characters with rank 3 item (3*)
Stratum 5 - designed for characters with rank 4 item (4*)
Stratum 6 - designed for characters with rank 5 item (5*)
I don't know what makes you think they're going to add Stratum 7 and 8. If they are, then introducing 6* and 7* items would be logical consequence.
Of course unless that "Redux" thing means Clockworks will be made totally anew, without Tiers, Stratum and other stuff that made us fell in love with SK.
Anyway, I'm a true follower of Ockham and I believe simplest solution is true one. Developers needs more people to by energy to compensate for removal of Mist Energy, free crafting and other disastrous decisions they have made recently. I don't like the way they're doing it.
I was quite a dedicated player and I have been always buying energy during promos (several Explorer Packs, Battle Pack, Starter Pack, 2 packs with Rose Regalia, 2 packs with Valkyrie Wings, 2 packs with Dragon Wings, Solstice Pack, Guardians Pack). I even purchased some energy during recolours promo (Hunter pack, pack with Rose Reagalia Redux) even though I think recolouring is somewhat cheap way of making promos. Since latest energy system make-over I have been also buying promo boxes from Depot (3 Gourmet Boxes, 2 Obsidian Boxes). But I refuse to buy Fire Crystals. I just don't like that business model. Fancy costumes to show support is one thing. Forcing players to pay for basic game feature is another.