So, update. My kid reached out to Cal Poly SLO admissions to get a definitive answer, and surprisingly, this was the response: “I would say that that work experience absolutely has to do with your intended major. :)” (Yes, the smiley face is part of this direct quote.)
I’m thinking maybe he should reach out a second time just to double check, on the off chance that the person was a new hire, or something, however, that’s what they said.