I think the unique thing about this case is not specifically the "voice theft", but that OpenAI specifically asked for permission and were denied, which eliminates most of the usual plausible deniability that gets trotted out in these cases.
>>creato+(OP)
Is it really better to take something without asking than to ask and then take it anyway if denied?
In my mind these are close to being equally shitty, but not asking is a shittier because the victim won't necessarily know they've been exploited, which limits the actions they will be able to take to rectify matters.