From the announcement:
Necromunda Is Back!
It’s been more than a decade since we last visited the Underhive, but very soon you’ll be able to battle it out in the depths of Hive Primus.
If you’re new to the hobby, you may not be familiar with Necromunda – or perhaps you’ve only heard about it from the fond memories of other hobbyists. Necromunda dives into the underworld of the Imperium, allowing players to control their own Hive Gang – a pack of ruthless criminal killers augmented with black-market cybernetics, gene modifications and scavenged weaponry. Where Warhammer 40,000 puts you at the head of an army, in Necromunda, the scale is much smaller but the action is just as intense – every single Ganger counts.