10 of billions of dollars of media can be cheaply dubbed and altered.

I guess.

I'd just be happy with some Russian Scifi dubbed for the first time to begin.

On Wish Dragon I was disappointed they referenced the game as chess, when clearly that was pandering to the English audience. It would be nice to fix that, it doesn't feel like that was the directors decision.

But sure, George Lucas could stuff a lot of dialogue up.

To me the concerns that original dialog will be lost are simply not real. If anything they can be restored if you have just the subtitles/original script

I think fan fiction re-dubbing could be really interesting. I think some movies could be turned around on the dialogue alone.

But to fear the authenticity of movies is at stake while spreading the worlds media across cultures, no, to many data hoarders to be losing original audio these days, I think we are safe.

And obviously on Khan Academy etc you do want to alter it. That's the point. Fix mistakes. Change things for different cultures. Speak a little clearer.

This will be great for dubbing, no doubt. I was thinking more about the negative aspects, though. Altering historical recordings to spread misinformation, fake audio recordings "exposing" politicians getting leaked to the public,... things like that.