It's not. The original comment in this chain was drawing parallel to a lawsuit in which someone intentionally took steps to impersonate an actor.
This situation is a voice actor using their "natural voice" as a source of work.
If a lawsuit barring OpenAI from using this voice actor is successful, due to similarities to a more famous actor, that puts this voice actor's future potential at risk for companies actively wanting to avoid potential for litigation.
Suggesting a calming female persona as a real time always present life assistant draws parallel to a movie about a calming female persona that is a real time always present life assistant is not a smoking gun of impropriety.
Pursuing a more famous name to attach to marketing is certainly worth paying a premium over a lesser known voice actor and again is not a smoking gun.
Sky voice has been around for a very long time in the OpenAI app dating back to early 2023. No one was drawing similarities or crying foul and decrying how it "sounds just like Scarlett" ..