I think pulling the voice right away is the right strategy. Even if they fight and lose a court case, losing the rights to the Sky voice, will there really be a lot of damages just for including it in a demo video? Probably not. And what's the upside of fighting? Do you really want a voice that sounds like Scarlett Johansson and reminds people of this whole thing? OpenAI should just compromise, take down the voice, move on, and focus on making something people want.
I think what confuses me is if you have made a business decision like this did nobody think about the downside case? Clearly not because they backed out so quickly.