​Prior to the 7.0 update, there was an assault wargear that was unlocked through completing operations and pvp. I'm referencing the relic level wargear that has the skull and wings that go on top of the power pack. Post update, this is now locked with an Assault Class Prestige Level 4 requirement. Additionally, when looking at the full customization set UI "Relic Secundus", requires 35 battles in Operations or Eternal War mode. I haven't seen any other class where an individual customization piece was re-locked by the 7.0 update.