I've seen pull request interactions where a moderating authority would have made all the difference.

We mostly accept the need these days to moderate other online social behavior, like on HN, to reduce potential damage from ego/politics. Hopefully the need is lower in a professional environment like SD, but I could still see it being useful when things go off the rails.

I suspect manager here does not mean high level manager, but someone who has at most a dozen or two people under them.

And yes, effective culture around PRs seems valuable. My current team seems to have very inconsistent expectations, and would benefit from someone with authority steering people in the right direction.