The hive mind bit was kind of cool, but the bit where it seemed to matter that it was trying to sell the guy on why it felt the God-King lied to humanity was unexpected. I do like the idea of GDF's Alien Hives breaking away from the GW Nid idea of them being just a smart all consuming swarm.
The Dark Elf Raider involvement as having 'made a deal' with the Alien Hives also hints at them being able to be negotiated with at all too. I like that.