Yeah, to be honest I’m a bit worried studios might use this technology to start changing lines in already released movies, so subtly only film buffs who know the film line-for-line would ever notice.
Even done for well-intentioned reasons (like removing slurs from old-timey movies) it would open up a whole moral and ethical can of worms about whitewashing the past. And I have zero faith in studios to do it for well-intentioned reasons-- especially not when they’re under pressure by religious fanatics, authoritarian governments, etc.
Good points, but even so I’d still rather have a less-than-optimal sub that still lined up with what the characters were saying in the dub, than having the two conflict with each other. (Maybe if you turn the dub off, the subs could be replaced with the better sub-only version?)