> For a case that doesn't involve AI at all, consider situations where a voice actor in a cartoon is replaced (sometimes while still alive) by someone who can perform a voice that sounds the same. Decisively not illegal.

Because there are contractual clauses. Do you think Hank Azaria owns the voice of 'Homer Simpson'? Or does Fox own that? It would be crazy to develop a show and then be held hostage to your voice actors for all future shows - what if they get hit by a car?