No, I don't think you can walk this back:
they tried to get Scarlet to do the voice and after she declined OpenAI found someone
This is exactly the question the Washington Post set out to answer, and the answer is "no": that didn't happen.
There’s no walking back. My initial post said: “used Sky from the beginning” If they had released Sky’s voice publicly before contacting Scarlet it would have been a different situation, but they made the decision afterwards.
Simply recording Sky’s voice beforehand doesn’t imply a different intent. This isn’t animation where you’re trying to match two mediums and you want the actors recording first. Having a similar voice to work with would have been useful internally to know if they wanted to pay what it might cost to use her voice.
If they had released the voice they could have argued they wanted something different, but by waiting and going with Sky after the negotiations failed it’s a different matter.