Well, there are differing degrees of 'dead'. Remember, Chaos Dwarves were 'dead' for a long time, but GW still gave them updated rules (albeit in fairly streamlined form) that kept them legal to play via ravening hordes, and the chaos dwarf community rallied together to update and expand those rules themselves, and third party companies capable of operating at smaller production scales than GW moved in to satisfy that demand with new 'chaos dwarf' models. Chaos dwarf armies using third party models and the de-facto "official" chaos dwarf homebrew army book were a not-that-uncommon sight at a number of tournaments. And eventually even GW came to recognize that popularity, with Forgeworld putting out chaos dwarf rules and models of their own.
So long as you don't play exclusively in a first party store, I wouldn't expect any faction or aesthetic that doesn't make it into the age of sigmar to be lacking in non-GW support sufficient to keep it playable in some form.
The issue is more of game style. Just going from the models, this looks like a fantasy themed 40k (seriously, the 40k set looks almost suspiciously similar to the chaos lineup in dark vengence, just with beefier cultists). Maybe the models can group up to form shield walls or whatever, but this is not a regiment scale battle game, and if that's what you want to play, then you're options will become progressively more limited as time goes on, unless Kings of War manages to establish itself as the Pathfinder to Age of Sigmar's 4e. Note this is not meant to be disparaging to either game, I enjoyed both Pathfinder and 4e for what the are/were.
My comments on the site weren't really calling into question whether Carpe Noctem would persist. I have no doubt of that. Rather, I'm merely wondering what form that persistence will take. Age of Sigmar very much looks like a new game, not a new edition of the game this site has been dedicated to for so long. So does Carpe Noctem stick exclusively to the old game? If it adopts the new game, will AoS subforums replace those for 8th edition, relegating 8e talk to the archive section? Or since they are two separate games, will new, separate forums be established for AoS discussion, with the 8e tactical and battle report threads left intact?
And if we're adopting entirely new games, why stop with just the one? Why not forum sections for the undead factions in Kings of War or Warmachine? I mean, ok, maybe not warmachine, as cryx players have more established communities elsewhere, but my impression was that the site admins here have a friendly relationship with the mantic folks, a set of forums for kings of war general and tactical discussions might be worth considering, if the site opts for the 'add rather than replace' route.