You weren't kidding. They're an anthropologist who went into design a few years ago because "it's not terribly employable" and as of less than 1 year ago was a "Lead Design Engineer at Normally"? This is GitHub Staff eng steering the direction of the concept of PRs?

“Few years ago” is about a decade in design, to be fair.

I’m not sure what staff level means at GitHub, but at some other companies it’s just “senior++”, and people with 10yoe get that title quite often.