In the very old
40k Compendium there was the mention of Operation Carthage
Legio cohorts are occasionally attached to campaigning Marine Chapters, such as during Operation Carthage (the Second Pacification of Isstvan V). When the Desert Lions Chapter took the planet's defence forts they were preceded by a complete Legio Cohort of Robots. The Robots had been programmed to advance in an apparently mindless fashion, and proved easy targets for the defenders. However, the Desert Lions used the opportunity to map out the defenders' fire-plans and blind spots. In the Lions' ensuing assault only seven Marines were lost.
All the surviving Robots were inducted into the Chapter as honorary members as a mark of respect
Bravery is stronger than Adamantium. One is the stuff of the soul-forges, the other an illusion of safety created by fools. Adamantium walls cannot keep us out! We have the courage of the Emperor! And in the Emperor's name... ATTACK!! ATTACK!! NO PRISONERS!! - Chaplain Gonzago
There is nothing mentioned of it now, like jaredmm says, it's likely been removed from star chart. Although in the Night Lords series Tsagualsa was settled on by, I think they were space wanderers, so it is possibly that it could be resettled without the Imperium knowing. It's unlikely though, it would have the same level of protection from the Inquisition as the Traitor Legion homeworlds.