I think they are Slaves to Darkness, the Warqueen is listed under Slaves to Darkness. My bet is the marauder kits, at least, will be discontinued around the time Darkoath get a full army treatment and probably more of the range too.
I’m ok with that too. There are a few classic models amongst the characters and I still like the Chaos Warriors, but for the most part I think it’s time to move on.
Edit: Actually, I’d really love for GW to blinside us and make Darkoath a Destruction faction. Never happen, but it would be kinda cool. I will now remove my tinfoil hat.