So is the Chaos Marine codex going to bring forth legions? A White Dwarf update? Here is a rumor discussing unlocking Legions in the new codex. theDarkGeneral believes we will have Legions in the new codex. Please take with a good amount of salt, and only time will tell.
via theDarkGeneral
You won't need special characters to unlock Legion Armies, however some of them will make certain unit(s) much better. The flexibility of taking a "regular" Chaos Lord, or Sorcerer, or Daemon Prince, OR Aspiring Champion(s) will still be there, which of course will be able to lead your Night Lords or World Eaters or Iron Warriors.
Just want to bring something up I mentioned months ago...but most didn't pick up on it...right now everyone keeps on talking about the 4 basic Cult units...but what if GW adds a "basic Cult unit" for the other 6 Legions? I've already mentioned Raptors becoming Cult unit for Night Lords...
Now think about how an HQ will move unit slots for specific "Cult units" from one spot to another. AND if we go to percentages there will no longer be the worry of "just 3 Elites or Heavies or Fast Attack"...
*edited: And not everything will move to or be able to count as a Troop...some may move from Heavy to Elite or count as both...