I realise that for dubbing (and voice actors in general), they have the least amount of "potential fallback legal protections" in the context of automation via generative AI:

Translating? Machine translation is already well established.

Copyright? IIRC the most popular voice generation company (ElevenLabs) uses copyright-safe models, where the sources for the base model were already consenting.

Likeness? As you said, just use a synthetic voice.

Replacement of jobs? Not really a legal issue. It's not much worse than self checkouts or driverless cars, for example. The only reason we're talking about it is because it affects white-collar workers and not blue-collar workers, and voice actors are more likely to be celebrities than cashiers, for example.