If you haven't played with recent video tools, you might think this is a "someday in the future concern." But the current off-the-shelf tools for transforming one actor into another are mind-blowing: https://www.youtube.com/watch?v=eIJXOU83fqE&t=0s

And that's just what's available off-the-shelf, not what specialized studios are doing with huge budgets. The Marvel movies are already close to being "animated movies in a live-action style". Even basic helicopter shots flying over real-life locations like the coast of California are totally CGI because it's easier to animate than get a permit. Actors entire bodies will be replaced on a whim because they didn't like the costume choice. Putting a new face on someone is not that big of a deal.