Kinda. PI is principal investigator and usually they’re a professor with a grant (the grant being the thing they are the principal of investigating). That part is right. But they’re not really directly in the review loop. For some fields where things are small enough that folks can recognize style such as it exists, you could see reviewers passing over unfamiliar work and promoting familiar work. That was not the issue.

The issue was that it still was kind of hard to produce crappy mid rate papers, so you kind of needed the infrastructure of a small lab to do that. Now you don’t. The success rate for those mediocre papers produced by grad students and postdocs will go way down. It is possible that will cease to be a useful signal for those early career researchers.