They are trying to wriggle out of providing insight into how that voice was derived at all (like Google with the 100% of damages check). It would really suck for OpenAI if, for example, Altman had at some point emailed his team to ensure the soundalike was “as indistinguishable from Scarlet’s performance in HER as possible.“
Public figures own their likeness and control its use. Not to mention that in this case OA is playing chicken with studios as well. Not a great time to do so, given their stated hopes of supplanting 99% of existing Hollywood creatives.