On something like a PR review I would. But on anything that would involve private information such as the background, gender, photographs and/or video as well as other writings by the subject I think you'd be right.

It's just that it is fairly trivial to present a PR to a machine in such a way that it can only comment on the differences in the code. I would find it surprising if that somehow led to a bias about the author. Can you give an example of how you think that would creep into such an interaction?