Curious to know if 20-30 years ago, as graphic design tools got better, were people freaking out about being able to superimpose another person's face on a the body of p*rnstar?
Superimposing people's faces on to porn star's bodies happened/s, but does anyone care really even notice or care about it now days? For the most part, of course not.
So why should we care about porn videos? What makes them so different? The whole concern smells like typical media hype (i.e. yay - we get to write about AI + Porn - instant clickbait) that nobody will be able to stop and nobody will even care about in 1-2 years: e.g. "oh, yah, another deepfake of <(politician|actress|colleague^)> in a porn film - how incredibly creative".
^ Incidentally, this was made light of in the British version of The Office where a modified image of the boss, David Brent, was sent around the office. If it's joked about harmlessly on mainstream TV, it's probably not a huge concern.