I used to work for a company that contracted out programmers to a defense contractor (Northrup Grumman). It honestly never even occurred to me to redact out the stuff I worked on when I put it in my resume. Nobody said anything about that when I left the company, even though I’d gotten a security clearance to work at NG in the first place. I wonder if your “redacted” person just did it themselves to create a sense of mystery.