Like I'm sure that some relative of Elvis Presley was paid for the Elvis movie that was recently released, but is anyone going to get paid for those new Napoleon movie/miniseries?
Headline actors are inevitably going to be (already are?) selling the rights to their voice and likeness, setting up perpetual revenue streams for their estates, and in the next few years the parameters of those rights will almost assuredly be in every contract.
That could be amended in an explicit contract or quit the union. Say you are very sick/old/whatever/dontcare and need some money and have not had a gig in 10 years? I am will to bet we see a few of those soon. Then soon after the rise of the 'scanned' actor with no such contract but one that gives away those likenesses. They will be bought in packs like game assets.
>It's illegal to use someone's likeness without their knowledge in a lot of places.
It's illegal to use their likeness claiming that it is actually them. I fail to see how AI voices are legally any different at all than using a human impersonator.