Bodily autonomy is absolutely the right way to frame this. But that of the current body and capacities is what must be valued, not some hypothetical that may have been before an accident or transformation or puberty or whatever.
Whether someone originally consented to their powers or not, they are a part of who they are now. If they're of the mind to change that--in either direction--the government should not be facilitating, voting on it, or otherwise officially involving itself in that sort of personal decision, particularly when abuse threatens potentially every superpowered person here.