Or even gains control of them. You do see some examples of this in the Third Grey Knights novel, where a lot of the most powerful servants of Khorne there are essentially choosing their form (Admittedly, the more powerful choose even better ones - like the Dragon Guy).
But I'm wondering how possible it will be to try and toe the line, doing things for Chaos without being horrifically changed. Admittedly, this could easily be a problem in not gaining as much power as those who embrace them. But I am curious if this will even be an option. After all, some of the great champions seem to not have any obvious ones at all.
Or even if we'll have some broad way to influence our mutations. Even if it is so far as make your roll, and somehow able to choose to take the one directly above or below potentially?
I am guessing the NDA sorts can't answer, so this is currently conjecture and hopes. But you never know!