The part that's interesting to me is for characters more than actors - but as someone else said - the AI also needs to emulate their style and such for it to be a compelling "performance". That said, I believe it'll be possible if there's enough pre-existing content to train on. GPT already can create written content "in the style of" well enough to be amazing to most average people.

What's interesting is how much these will be used followed. I'm thinking to many of the franchises - like Star Trek - where they've re-cast the characters, but current writing is so... let's say different.... that it still doesn't' really feel like the character. I'm not attached to Shatner - I don't watch shows because he's in them. I do like his portrayal of Kirk in the TV show and movies. But there's the current Actors (like when Chris Pine did his movies) don't like to "do an impression". Pine can and a good one - there's a SNL skit where he actually does a Shatner impression, and it was very on for the character IMO.

Are the current actors right? IDK - we don't usually get any sort of A/B testing for the wide public. That said - given the fan backlash on the newer franchise productions - there's a viewership who presumably would like a full recreation. Ahhh, but the other critique would be - it's not just the current actors, heck, many are excellent - it's the writing. I'd argue that's (like I said above) easier to do with current AI - if the producers and studios let an AI do an actual "in the style of" script.

What's my point? Hmmm, I'm actually interested in more affordable creation of new content in franchises that I liked, to the extent it actually fits with the existing content. I think we need to separate the characters from the actors - much like animated characters have been.