With all the talk of the primaris space marines being thrown around I was trying to consider how chaos will get their hands on these guys. At this point it seems that they may be immune to the allure of chaos so the only realistic way I could come up with is if Fabius Bile starts cloning them. Considering he has cloned primarchs in the past I think it may be safe to say that he is our best hope of getting some of these guys.