Which is what this would be in the not-stupid version of events: they hired a voice actress for the rights to create the voice, she was paid, and then is basically told by the courts "actually you're unhireable because you sound too much like an already rich and famous person".
The issue of course is that OpenAIs reactions so far don't seem to indicate that they're actually confident they can prove this or that this is the case. Coz if this is actually the case, they're going about handling this in the dumbest possible way.