And while popular existing actors might be able to demand enourmous compensation right now, I'm not really sure what level of compensation they deserve. In the end, we are probably moving towards entirely fictional actors for most movies anyway.
I just kind of shudder at the thought of a voice actor signing over rights to their voice without appropriate compensation and their career just vanishing (assuming AI gets good enough to outright replace them completely)
In my view, any human that signs over such rights deserves to be well-compensated upfront and should ensure they have a contract that pays them significant royalties for each subsequent use. I suppose maybe the most important part of all of this work-wise is just to have a reasonable contract so one retains some control.
Of course, all of this I say with the disclaimer that I'm not certain I think anyone should sign over such rights. I freely admit I come at this from a perspective that is biased against audio/visual/text-generating (and potentially other forms of) AI, unless it is significantly reigned in through restrictions/regulations. I do not look forward to an AI-dominated future of soulless pseudo-art generated by entertainment corporations.
They already do this regularly in movies, it's part of the ADR process [0]. You've probably heard it many times and not even noticed.