Maybe, but it's not that easy. You're generally going to see a 3-lines-of-context diff, and the reviewer won't necessarily have the idea to read the entire file

Maybe, but it's not that easy. You're generally going to see a 3-lines-of-context diff, and the reviewer won't necessarily have the idea to read the entire file (or worse, go poking elsewhere in the codebase) to see if comments deserve changing.