"One day, the technique may even allow us to gaze into the faces of extinct human-like species that interbred with our own ancestors."
I don't know how accurate that statement is. They can predict human faces because they can look at examples of DNA and the paired human face, they would have to use unsupervised machine learning for extinct species and have no real way to validate it.
This is possible as the molecular machinery for translating a DNA sequence into a 3-D structure is highly conserved - basically if you can convert modern human DNA into a face then you can convert other close relatives as well.
If you developed it to give consistently good results on other primates and then other mammals, then you could probably feel pretty confident about things such as cranial shape, eye color etc. etc.
We could probably feel pretty confident about eye color right now. What color are gorilla eyes? Howler monkey eyes? Humans barely vary in eye color at all; fancy European eye colors are a very recent phenomenon.
I don't know how accurate that statement is. They can predict human faces because they can look at examples of DNA and the paired human face, they would have to use unsupervised machine learning for extinct species and have no real way to validate it.